Device, method and system for detecting unwanted conversational media session

ABSTRACT

Some embodiments of the invention relate to a method and a system for detecting unwanted conversational media session data. In accordance with one aspect of the invention, a method of detecting unwanted conversation media session data according to some embodiments of the invention may include calculating two or more progressive similarity scores each with respect to a different instant during a progress of a real-time conversational media session, wherein each of said scores is associated with a similarity between the conversational media session&#39;s media data that was available at the associated instant and a reference data item corresponding to media data of a previous conversational media session, and evaluating progressive similarity between the real-time conversational media session and the reference data item based upon the two or more progressive similarity scores.

FIELD OF THE INVENTION

This invention relates to a device, a method and a system for detectingunwanted conversational media sessions and for enabling control overconversational media traffic.

BACKGROUND OF THE INVENTION

Real-time conversational media sessions, such as conversationaltelephony services, for example, are known in the art. Conversationalmedia sessions provide bidirectional real-time transfer of motion video,voice, text and other data and various combinations thereof betweenusers at two or more locations. Conversational media services aredescribed, for example, by a variety of standards, such as the IETF'sSIP (Session Initiation Protocol) family of standards, and the ITU-TH.323 family of standards. Contemporary conversational media servicesinclude for example, VoIP (Voice over IP) also referred to asIP-Telephony, video telephony, and real-time text telephony.

Conversational media services over packet switched networks, inparticular IP (Internet Protocol) networks, present users andorganizations with new challenges, including the need to handle unwantedsessions and unwanted data within sessions. Unwanted sessions can becomean annoyance to users and organizations and may potentially compromisesecurity, particularly when the user or the organization is subject to abulk of unwanted sessions. Due to the low cost of generating a mass ofunwanted calls (or sessions) over packet data networks (no payment persession duration or per communication line, dedicated and expensivehardware is not required), such unwanted sessions are expected to becomewidespread unless effective solutions are devised.

SUMMARY OF THE INVENTION

It is an object of some embodiments of the invention to provide adevice, a method and a system for detecting unwanted conversationalmedia sessions (hereinafter: “CMS”). It is an object of furtherembodiments of the invention to provide a device, a method and a systemfor enabling control over conversational media traffic.

Some embodiments of the invention relate to a system and a method ofdetecting unwanted conversational media sessions or unwantedconversational media session data. According to some aspects of theinvention, a method of detecting unwanted conversational media sessionsmay include calculating two or more progressive similarity scores eachwith respect to a different instant during a progress of a real-timeCMS, wherein each of the scores is associated with a similarity betweenthe real-time CMS media data that is available at the associated instantand a reference data item corresponding to media data of a previous CMS,and evaluating progressive similarity between the real-time CMS and thereference data item based upon the two or more progressive similarityscores. According to further embodiments of the invention theprogressive similarity scores may be calculated on-the-fly during theprogress of the real-time CMS.

According to further embodiments of the invention, a progressivesimilarity criterion may be applied, such that progressive similarity isestablished when the two or more progressive similarity scores are incompliance with the progressive similarity criterion. According tofurther embodiments of the invention, the progressive similaritycriterion may be sensitive to the amount of media data associated with asimilarity score.

According to still further embodiments of the invention, the real-timeCMS may be discontinued in case it is established that the progressivesimilarity between the real-time CMS and a reference data item is incompliance with the progressive similarity criterion. According to someembodiments of the invention, in case the progressive similarity betweenthe real-time CMS and a reference data item does not comply with theprogressive similarity criterion, the similarity evaluation process maybe halted, in which case the real-time CMS and the reference data itemmay be determined to be dissimilar. However, in accordance with afurther embodiments of the invention, in case the progressive similaritybetween the real-time CMS and a reference data item does not comply withthe progressive similarity criterion, the similarity evaluation processmay either be halted, for example, in case the real-time CMS and thereference data item are determined to be dissimilar, or the calculationof the progressive similarity scores may continue, and at least oneadditional progressive similarity score may be calculated for thereal-time CMS and the reference data as more media data becomesavailable and the similarity evaluation may be repeated taking intoconsideration the additional progressive similarity score. According tosome embodiments of the invention, in case the progressive similaritybetween the real-time CMS and a reference data item does not comply withthe progressive similarity criterion, the decision whether to halt theprogressive similarity evaluation or whether to continue and calculatean additional progressive similarity score may depend upon the currentprogressive similarity scores and a progressive similarity criterion.

According to further aspects of the invention, a method of detectingunwanted conversational media sessions may include obtaining a sequenceof significant attributes directly from a bit-stream associated with areal-time CMS, and evaluating similarity between the sequence ofsignificant attributes associated with the real-time CMS and a referencedata item corresponding to a sequence of significant attributes of abit-stream associated with a previous CMS. According to furtherembodiments of the invention, the significant attributes may include oneor more of the following: gain parameters of adapted and/or fixedcodebooks, spectral parameters coded as Line Spectral Pair.

According to further embodiments of the invention, the real-time CMS maybe discontinued upon establishing that the similarity the betweensequence of significant attributes associated with the real-time CMS anda reference data item is above a certain threshold. According to stillfurther embodiments of the invention, a CMS traffic control rule may begenerated based upon the similarity between the sequence of significantattributes associated with the real-time CMS and the reference data itemfor enabling CMS traffic control. The traffic control rule may begenerated in case the similarity the between sequence of significantattributes associated with the real-time CMS and reference data item isabove a certain threshold.

According to still further aspects of the invention, there is provided asystem and a method of detecting unwanted conversational media sessionswhich includes utilizing a fake conversation client. According to someembodiments of the invention, the fake conversation client may beutilized in a manner to cause an originator of real-time CMS data tosetup a real-time CMS with the fake conversation client. The mediaportion of the real-time CMS data may then be used to generate areference data item. The reference data item may be published in amanner to enable a client in receipt of the reference data item tocontrol incoming real-time CMS traffic based upon a similarity betweenthe incoming real-time CMS traffic and the reference data item.

According to some embodiments of the invention, the fake conversationclient may be utilized to interface the real-time CMS data to enablereceipt thereof at the fake conversation client. According to furtherembodiments of the invention, the fake conversation client may befurther adapted to generate synthetic CMS data intended for causing theoriginator of the real-time CMS to provide the fake conversation clientwith further real-time CMS data. According to yet further embodiments ofthe invention, generating synthetic CMS data may include invokingprerecorded CMS data in response to the incoming real-time CMS data.

According to further aspects of the invention, a method of detectingunwanted conversational media sessions may include providing aconversation proxy positioned between an originator of real-time CMS anda client in a manner to cause the originator to setup a real-time CMSintended for the client through the proxy. The real-time CMS's mediadata may be evaluated for similarity with a reference data itemcorresponding to media data associated with a previous CMS received atthe conversation proxy, and the real-time CMS may be controlled inaccordance with a similarity between the real-time CMS's media data andreference data item associated with media data of a previous CMS.

According to some embodiments of the invention, the conversation proxymay be configured to interface the real-time CMS data arriving from theoriginator and the real-time CMS data arriving from the client to enablesetting up of the of the real-time CMS between the originator and theclient through the proxy. According to further embodiments of theinvention, the proxy may be adapted to establish the real-time CMSintended for the client between the originator and the conversationproxy using signaling data associated with the intended client, and toestablish a real-time CMS between the conversation proxy and the clientusing signaling data associated with the originator, thereby enablingCMS data exchanges between the originator and the client through theproxy.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to understand the invention and to see how it may be carriedout in practice, a preferred embodiment will now be described, by way ofnon-limiting example only, with reference to the accompanying drawings,in which:

FIG. 1 is a block diagram illustration of a system for detectingunwanted conversational media sessions, according to some embodiments ofthe invention;

FIG. 2 is a graphical illustration of time ordered sequence ofparameters representing a real-time voice over IP (VoIP) sessionreceived from an originator; and of reference data items which include(each) a time ordered sequence of parameters representing at least aportion of a previous CMS, according to some embodiments of theinvention;

FIG. 3 is a block diagram of an optional implementation of a system fordetecting unwanted conversational media sessions, according to someembodiments of the invention;

FIG. 4 is a simplified block diagram illustration of certainimplementations of a system configured for implementing a directbit-stream similarity evaluation process for detecting unwanted CMStraffic;

FIG. 5 is a symbolic representation of a time ordered sequence ofsignificant attributes obtained from a bit-stream corresponding to aportion of a real-time CMS and of reference data items which include(each) data in respect of significant attributes obtained from abit-stream corresponding to a portion of a previous CMS, according tosome embodiments of the invention;

FIG. 6 is a simplified block diagram illustration of certainimplementations of a system configured for implementing a packet arrivaltime similarity evaluation process for detecting unwanted CMS traffic;

FIG. 7 is a symbolic representation of a stream of data packetscorresponding to a portion of a real-time CMS and of reference dataitems which include (each) a stream of data packets corresponding to atleast a portion of a previous CMS, according to some embodiments of theinvention;

FIG. 8 is a block diagram illustration of a system for enablingdetection of unwanted CMS traffic which includes a fake CMS client,according to some embodiments of the invention; and

FIG. 9 is a block diagram illustration of a system for detectingunwanted CMS traffic which includes a CMS proxy, according to someembodiments of the invention.

It will be appreciated that for simplicity and clarity of illustration,elements shown in the figures have not necessarily been drawn to scale.For example, the dimensions of some of the elements may be exaggeratedrelative to other elements for clarity. Further, where consideredappropriate, reference numerals may be repeated among the figures toindicate corresponding or analogous elements.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

In the following detailed description, numerous specific details are setforth in order to provide a thorough understanding of the invention.However, it will be understood by those skilled in the art that thepresent invention may be practiced without these specific details. Inother instances, well-known methods, procedures and components have notbeen described in detail so as not to obscure the present invention.

Unless specifically stated otherwise, as apparent from the followingdiscussions, it is appreciated that throughout the specificationdiscussions utilizing terms such as “processing”, “computing”,“calculating”, “determining”, “generating”, “assigning” or the like,refer to the action and/or processes of a computer or computing system,or similar electronic computing device, that manipulate and/or transformdata represented as physical, such as electronic, quantities within thecomputing system's registers and/or memories into other data similarlyrepresented as physical quantities within the computing system'smemories, registers or other such information storage, transmission ordisplay devices.

Embodiments of the present invention may include apparatuses forperforming the operations herein. This apparatus may be speciallyconstructed for the desired purposes, or it may comprise a generalpurpose computer selectively activated or reconfigured by a computerprogram stored in the computer. Such a computer program may be stored ina computer readable storage medium, such as, but not limited to, anytype of disk including floppy disks, optical disks, CD-ROMs,magnetic-optical disks, read-only memories (ROMs), random accessmemories (RAMs) electrically programmable read-only memories (EPROMs),electrically erasable and programmable read only memories (EEPROMs),magnetic or optical cards, or any other type of media suitable forstoring electronic instructions, and capable of being coupled to acomputer system bus.

The processes and displays presented herein are not inherently relatedto any particular computer or other apparatus. Various general purposesystems may be used with programs in accordance with the teachingsherein, or it may prove convenient to construct a more specializedapparatus to perform the desired method. The desired structure for avariety of these systems will appear from the description below. Inaddition, embodiments of the present invention are not described withreference to any particular programming language. It will be appreciatedthat a variety of programming languages may be used to implement theteachings of the inventions as described herein.

Throughout the specification and the claims reference is made to theterm “session” either independently or as part of the term“conversational media session”, which is sometimes abbreviated as “CMS”.The term “session” shall be used to describe a series of interactionsbetween two or more communication end nodes that occur during the spanof a single connection. Typically, one end node known as “an originator”requests a connection with another specified end node known as “arecipient” or as “an intended recipient” and if the intended recipientreplies, agreeing to the connection, the end nodes take turns exchangingcommands and data (“talking to each other”). The session begins when theconnection is established at both ends and terminates when theconnection is ended. It should be appreciated that throughout thespecification, unless specifically stated otherwise, any reference madeto a “session” shall include a portion of a session.

Throughout the specification and the claims reference is made to theterm “conversational media session” or in abbreviation “CMS”. The term“conversational media session” or “CMS” shall be used to describe anybidirectional (or multidirectional) real-time session involving theexchange of media between two or more nodes over a network and/or aportion of such bidirectional real-time session involving the exchangeof media between two or more nodes over a network. There are varioustypes of real-time CMS which are known in the art. CMS types may differfrom one another, for example, by the type of media which is supportedby a particular CMS and/or by the underlying protocol used to enable theCMS traffic. Although throughout the specification specific examples ofCMS protocols may be used, it would be appreciated that any reference toa particular type of CMS protocol is made by way of example and is notintended to limit the scope of the invention, unless specifically statedotherwise. Furthermore, it should be appreciated that embodiments of thepresent invention relate to any known in the present or yet to bedevised in the future CMS.

Throughout the specification and the claims reference is made to theterms “media data”, “CMS's media data” or the like. The terms “mediadata”, “CMS's media data” or the like shall be used to describe any datawhich is or which is part of the media portion of a CMS and inparticular the media portion of a real-time CMS. It would be appreciatedby those of ordinary skill in the art that the media portion of a CMS,constitutes the CMS's content. Various types of CMS support differentkinds of media. Examples include the IEFT's SIP (Session InitiationProtocol) family of standards, and the ITU-T's H.323 family ofstandards. Examples of media information or data include audio and videosignals, typically supported by RTP (Real time protocol), a part of bothfamilies of standards mentioned above.

It would be appreciated that these examples, as well as any otherexample or reference to a specific CMS media type made throughout thedescription is made by way of example and is not intended to limit thescope of the invention, unless specifically stated otherwise.Furthermore, it should be appreciated that embodiments of the presentinvention relate to any known in the present or yet to be devised in thefuture CMS.

Throughout the specification and the claims reference is made to theterm “signaling data” or the like. The term “signaling data” or the likeis used to describe any data pertaining to a real-time CMS that isintended for setting up, enabling, supporting, augmenting and/orcontrolling a real-time CMS session but which does not include theactual content or media data of the real-time CMS. Signaling data asused herein may include but is not limited to real-time CMS data whoseintended functionality is one or more of the following: session setup,session control and support, session resource allocation, sessionaugmentation, session tear down, etc.

Some embodiments of the invention relate to a system and a method ofdetecting unwanted conversational media sessions and/or of detecting anunwanted portion within conversational media sessions. Reference is nowmade to FIG. 1, which is a block diagram illustration of a system fordetecting unwanted conversational media sessions, according to someembodiments of the invention. In FIG. 1, there is illustrated a firstnetwork node 102 which is an originator of a real-time CMS and a secondnetwork node 104 which is an intended recipient of the real-time CMS.The originator 102 and the recipient 104 are operatively connectable toone another, for example, through a network 106. It would beappreciated, that although the terms “originator” and “recipient” areused throughout the specification and the claims to describe theparticipants of the real-time CMS, where the “originator” relates to thenode which initiates the real-time CMS and the “recipient” is theintended destination of the originator's communication. However, itshould be appreciated that during the real-time CMS data may be (but isnot necessarily) exchanged in the reverse direction, from the recipientto the originator, or in both directions—from the originator to therecipient and vice-versa. Furthermore, it should be appreciated that areal-time CMS may involve more than two participants (or nodes) and dataexchanges between the participants of the real-time CMS may also bemultidirectional. Such real-time CMS traffic is sometimes referred to asa “conference call”. Thus, it would be appreciated, that the real-timeCMS setup shown in FIG. 1 provides merely an example of a possiblereal-time CMS setup.

A system for detecting unwanted CMS data 110, according to someembodiments of the invention, is also shown in FIG. 1. The system fordetecting unwanted CMS data 110 may be associated with the intendedrecipient 104 of the real-time CMS, for example, the system 110 may beattached to the intended recipient 102 of the real-time CMS. The systemfor detecting unwanted CMS data 110 may include a progressive similarityevaluation module 112 (hereinafter: “PSE module”), and a referencedatabase 114. The reference database 114 may include a plurality ofreference data items. Each of the reference data items may be associatedwith a previous CMS or with a portion of a previous CMS. For example,data in respect of a previous CMS may be provided in various formsincluding, but not limited to, a recording of a previous CMS or of aportion of a previous CMS, a signature of a previous CMS (or of someportion thereof), a schematic representation providing progressionschemes of one or more components of the previous CMS, etc. A previousCMS as used herein may include any earlier CMS traffic which traversed(and possibly is still traversing) the network and which was interceptedor otherwise obtained (and possibly is still being intercepted). Theprevious CMS used for generating the reference data items may be eitherrandomly selected or may be selected in accordance with certaincriteria. Thus, the reference data items are based upon actual CMStraffic, rather than being some sort of a simulation of CMS traffic. Itwould be appreciated, that according to further embodiments of theinvention, the reference data items used in respect of a certainreal-time CMS may be associated with specific previous CMSs, such asprevious CMSs which were intended for the recipient of the currentreal-time CMS. However, according to further embodiments of theinvention, the reference data items that are used in respect of certainreal-time CMS may be associated with any previous CMS intercepted fromthe network, originating from any originator within the network anddirected towards any recipient, and not necessarily with a CMS which waspreviously received or which was intended to be received at the intendedrecipient. Further details in respect of embodiments of the inventionwhich relate to a system for detecting unwanted CMS data 110 whichenables procurement of data in respect of previous CMSs which are notspecifically associated with any particular originator and/or with anyparticular recipient or intended recipient shall be provided below.

The PSE module 112 may be adapted to implement a progressive similarityevaluation process. The progressive similarity evaluation processimplemented by the PSE module 112 may be based upon calculatingsimilarity measures during the progress of the real-time CMS, whereineach calculation is based upon the real-time CMS media data which hasbeen thus far accumulated and corresponding reference data which iscorrelated with one or more previous CMSs. Some embodiments of theinvention suggest a progressive similarity evaluation process which isbased upon the assumption that authentic CMSs cannot be identical orsubstantially identical to one another, especially if a plurality of CMSare identified as being virtually identical, and that even if thesessions are subjected to artificial modifications to avoid identicalsessions, the extent of the modifications is typically limited,particularly if a relatively large number of synthetic sessions aregenerated. It should be appreciated, the similarity evaluation modulesdescribed as part of some embodiments of the invention may be configuredto monitor and to process real-time CMS traffic in one direction, thedirection from the originator, and that communications in the otherdirection(s), such as from a recipient to the originator are not ofinterest to the similarity evaluation processes.

The similarity measure calculation may be an iterative process, suchthat during the progress or the real-time CMS at least two progressivesimilarity scores are calculated, each with respect to a differentinstant during the progress of the real-time CMS, and as the real-timeCMS progresses more and more media data becomes available, eachprogressive similarity score is also associated with a different portionof the real-time CMS's media data. It would be appreciated, thatreal-time CMS traffic should not be significantly delayed, and thatotherwise the flow of the conversation may be significantly compromised.On the other hand, in order to prevent or to reduce the harmful effectsof unwanted CMS traffic, the unwanted CMS should be prevented ifpossible, or at least discontinued as soon as possible. The progressivesimilarity evaluation process suggested in accordance with someembodiments of the invention for detecting unwanted CMS traffic mayoffer a desirable tradeoff in the sense that it enables relatively fastand reliable detection of similarity between a real-time CMS and aprevious CMS.

According to some embodiments of the invention, each progressivesimilarity score may be associated with the real-time CMS's media datathat was accumulated from the start of the real-time CMS and up to theinstant during the progress of the real-time CMS with which theprogressive similarity score is associated. According to otherembodiments of the invention, each progressive similarity score may beassociated with the real-time CMS's media data that was accumulatedsince the last instant in respect of which a previous progressivesimilarity score was calculated. According to some embodiments of theinvention, the progressive similarity evaluation process may proceeduntil enough data is accumulated to support a conclusion that thereal-time CMS and one or more of the reference data items are similar.According to further embodiments of the invention, the duration of theprogressive similarity evaluation process and/or the number ofprogressive similarity scores to be calculated may be predefined.According to still further embodiments of the invention, the duration ofthe progressive similarity evaluation process and/or the number ofprogressive similarity scores to be calculated may be dynamicallydetermined based upon one or more of the following: the real-time CMS'smedia data flow rate (how much media data is received per time unit);and the level of similarity between the real-time CMS and the referencedata items. In accordance with an optional embodiment of the invention,a first progressive similarity score is calculated in respect of apredefined instant during the progress of the real-time CMS, and basedon the first progressive similarity score, the PSE module 112 maydetermine how many additional progressive similarity scores should becalculated and/or when is the next instant(s) in respect of which thenext progressive similarity score(s) should be calculated and/or howmuch additional media data should be accumulated before the calculationof the next progressive similarity score(s).

According to some embodiments of the invention, a reference data itemmay include or may be generated based upon accumulated data in respectof a previous CMS or in respect of a portion of a previous CMS. Inaccordance with further embodiments of the invention, a reference dataitem may include a signature of a previous CMS. A signature of aprevious CMS may be a compressed representation of the previous CMS.According to further embodiments of the invention, a signature of aprevious CMS may include certain data which corresponds to one or morecomponents, characteristics or parameters which are associated with of aprevious CMS, and may either be compressed or not. For example, areference data item may include a time ordered sequence of amplitudelevels which correspond to the media data that originated from anoriginator of a previous CMS. The time ordered sequence of the amplitudelevels may reflect the progression plot of a certain parameter of themedia portion that originated from an originator of a previous CMS andmay be used to determine the progressive similarity between a mediaportion being originated from an originator of a real-time CMS and themedia portion that was originated by a previous originator as part of aprevious CMS, as will be described in further detail below.

According to some embodiments of the invention, the PSE module 112 maybe adapted to use the signaling data of a real-time CMS to pre-filterthe reference data items so as to reduce the amount of reference datathat needs to be processed as part of the progressive similarityevaluation process in respect of a certain real-time CMS. For example,as part of a progressive evaluation process implemented in respect of acertain real-time CMS, the PSE module 112 may be adapted to select fromthe reference database 114 only the reference data items that areassociated with relatively recent CMSs. According to a further example,as part of a progressive evaluation process implemented in respect of acertain real-time CMS, the PSE module 112 may be adapted to select fromthe reference database 114 only the reference data items that areassociated with CMSs having, for example, a common originator with thereal-time CMS, or whose originator is located within the same domain asthe originator of the real-time CMS. The reference database 114 may beimplemented as a central database and may provide services to variousPSE modules 112 distributed throughout the network, and each of the PSEmodules 112 may be adapted to obtain from the central reference database114 the reference data items that are pertinent to a certain real-timeCMS being evaluated for progressive similarity by that PSE module 112.

As mentioned above, the PSE module 112 may be adapted to evaluate aprogressive similarity between a real-time CMS and one or more referencedata items. A progressive similarity between a real-time CMS and areference data item may be determined based upon two or more progressivesimilarity scores. Each progressive similarity score may be based upon ameasure of similarity between the real-time CMS data available at acertain instant during the progress of the real-time CMS and a referencedata item or a portion of the reference data item. In accordance withsome embodiments of the invention, progressive similarity score may bebased upon a similarity between the real-time CMS data available at acertain instant during the progress of the real-time CMS and a portionof a reference data item which is correlated with a portion of aprevious CMS, where that portion of the previous CMS is equivalent tothe portion of the real-time CMS in respect of which the score is beingcalculated.

It should be appreciated that any presently known or yet to be devisedin the future method, technique or mathematical model which is suitablefor comparing two or more sets of values and for determining thesimilarity between the two sets of values may be used for calculatingthe progressive similarity scores. Each score calculated by the PSEmodule 112 is based upon a measure of similarity between media data of areal-time CMS that was available at an associated instant and areference data item or a portion of a reference data item, where thereference data item provides data in respect of media data of a previousCMS. It should be further appreciated that according to some embodimentsof the invention, the similarity measure technique implemented by thePSE module 112 for calculating progressive similarity may besubstantially straightforward in terms of computational complexity, toenable fast calculation across large amount of reference data, whilebeing insensitive to noise and certain modification (for example, toartificial modifications). For example, the similarity measure techniqueutilized by the PSE module 112 may provide various tolerance mechanismsso that insignificant alterations to the media data, such as, but notlimited to alterations to background or non-significant areas ofpictures or videos, are neutralized or are played down. Further detailsin respect of the relationship between the progressive similarityevaluation process and the progressive similarity scores shall beprovided below.

According to some embodiments of the invention, as part of theprogressive evaluation process, the PSE module 112 may select at leasttwo instants during the progress of the media portion of the real-timeCMS in respect of which a progressive similarity score is to becalculated. The PSE module 112 module may calculate a progressivesimilarity score in respect of each of the two or more instants thatwere selected by the PSE module 112. It would be appreciated that as thereal-time CMS progresses, more and more media becomes available, andthus, as each progressive similarity score is calculated in respect of adifferent instant during the progress of the real-time CMS, each scoremay relate to different media data. According to some embodiments of theinvention, each progressive similarity score may relate to the portionof a real-time CMS's media data that was received since the previousinstant in respect of which a progressive similarity score wascalculated. According to further embodiments of the invention, eachprogressive similarity score may relate to all the media data which hasbeen accumulated from the start of the media portion of the real-timeCMS and up to the instant in respect of which the score is calculated.

According to some embodiments of the invention, the two or more instantsin respect of which the progressive similarity scores are to becalculated may be predefined. For example, the PSE module 112 may beadapted to calculate a progressive similarity score in respect of each 1second period during the progress of the real-time CMS starting from thebeginning of the media portion of the CMS. In accordance with anotherexample, the PSE module 112 may be adapted to calculate a progressivesimilarity score in respect of each segment of 10 bytes of data madeavailable as part of the progress of the real-time CMS. According tofurther embodiments of the invention, the PSE module 112 may be adaptedto dynamically determine the next instant in respect of which the nextprogressive similarity score is to be calculated. The PSE module's 112decision as to the next instant in respect of which a progressivesimilarity score is to be calculated may depend on various parameters,including but not limited to, the rate at which the real-time CMS datais being received, the quality of the data being received (how muchsignificant information is received within a certain period of time),the previous progressive similarity scores and the number of previousprogressive similarity scores calculated thus far, etc. For example, ifthe incoming real-time CMS data includes a lengthy “silence” period, thePSE module 112 may delay the calculation of the progressive similarityscore until more “non-silence” data is received, so that the progressivesimilarity score is based not only on the “silence” period. According tostill further embodiments of the invention, some of the instants duringthe progress of the real-time CMS in respect of which a progressivesimilarity score is to be calculated may be predefined whereas otherinstants for which progressive similarity scores may be determined bythe PSE module 112 on-the-fly during the progress of the real-time CMS.

It should be further appreciated that, according to further embodimentsof the invention, as part of calculating a progressive similarity score,a portion of the reference data item may be compared with a portion ofthe real-time CMS, rather than the entire reference data item beingused. The PSE module 112 may be adapted to determine which portion ofthe reference data item is to be compared as part of each progressivesimilarity score calculation. According to some embodiments of theinvention, the portion of the reference data item that is to be comparedas part of calculating a certain progressive similarity score maycorrespond to the media data that was received from the beginning of themedia portion of the previous CMS with which that reference data item isassociated and up to the instant during the progress of the previous CMSwith which that score is associated. However, according to furtherembodiments of the invention, the PSE module 112 may be adapted toselect a different portion of the reference data item for calculating aprogressive similarity score in respect of a certain instant during theprogress of the real-time CMS, and that portion may not necessarilyoverlap with the instant during the progress of the real-time CMS. Forexample, as part of calculating a certain progressive similarity score,the PSE module 112 may be adapted to compare a certain portion of themedia data of a real-time CMS that is associated with a certain instantwith a portion of the reference data item which corresponds to a portionof a previous CMS that is associated with a different instant during theprogress of the previous CMS.

According to some embodiments of the invention, as part of calculating aprogressive similarity score, the PSE module 112 may be configured tocompare the portion of media data of the real-time CMS that wasavailable at the instant with which that score is associated with areference data item or some portion thereof that is associated withmedia data of a previous CMS or with a segment of a previous CMS.According to further embodiments of the invention, comparing the currentreal-time CMS with a reference data item may include comparing onlycertain components or characteristics of the current and previoussession(s), such as, for example, but not limited to acoustic frequencyvariation over time, amplitude of acoustic signals over time, comparingparameters calculated via parametric modeling of the signals, comparingfrequency-domain representations of the signals, etc.

Reference is now made to FIG. 2 which is a graphical illustration oftime ordered sequence of parameters representing a real-time voice overIP (VoIP) session 202 received from an originator; and of reference dataitems 204 and 206 which include (each) a time ordered sequence ofparameters representing at least a portion of a previous CMS, accordingto some embodiments of the invention. As mentioned above, according tosome embodiments of the invention, the PSE module 112 may be adapted tocalculate two or more progressive similarity scores, each with respectto a different instant during a progress of the real-time VoIP session202. The PSE module 112 may be adapted to calculate the progressivesimilarity scores on-the-fly, during the progress of the VoIP session202. For example, in FIG. 2, the PSE module 112 calculates a firstprogressive similarity score with respect to a first instant 232 duringthe progress of the VoIP session 202 and may proceed to calculate asecond progressive similarity score with respect to a second instant 234during the progress of the VoIP session 210. According to someembodiments of the invention, after the progressive similarity scorewith respect to the second instant 234 is calculated, the PSE module 112may proceed to evaluate the similarity between the real-time VoIP 210and the reference data items 204 and 206 based on the two similarityscores (the first being associated with instant 232 and the second beingassociated with instant 234). It would be appreciated that at instant234 more CMS media data from the originator of the sessions becomesavailable, since as the real-time VoIP session 210 further progressesmore and more media data from the originator is made available to thePSE module 112. In order to illustrate further embodiments of theinvention, the similarity evaluation process with respect to thereal-time VoIP session 202 and the reference data items 204 and 206shown in FIG. 2 may proceed further beyond the second instant 234 and athird progressive similarity score may be calculated for the real-timeVoIP session 202 and the reference data items 204 and 206 in respect ofa third instant 236 during the progress of the real-time VoIP session210. Further discussions of embodiments of the invention that areassociated with the calculation of the third progressive similarityscore shall be provided below.

According to some embodiments of the invention, the PSE module 112 maybe adapted to implement progressive similarity criteria. The progressivesimilarity criteria may specify under what conditions a real-time CMSshall be considered to be similar to a reference data item. Theprogressive similarity criteria may depend on various components orcharacteristics of the real-time CMS in respect of which the criteriaare to be applied. For example, as will be described in greater detailbelow, in case a certain real-time CMS belongs to a grey list relatingto various characteristics of real-time CMSs that may be consideredunwanted, the progressive similarity criteria that is to be applied inrespect of that real-time CMS may be more flexible in respect of areal-time CMS, so that the level of progressive similarity needed forconcluding in accordance with the progressive similarity threshold thatthe real-time CMS and a reference data item are similar, is relativelylow, and/or so that the quantity of real-time CMS data and/or the numberof progressive similarity scores needed for concluding in accordancewith the progressive similarity threshold that the real-time CMS and areference data item are similar, is relatively low, and should beconsidered progressive similarity.

The PSE module 112 may manage the progressive similarity evaluationprocess in respect of a certain pair of real-time CMS and a referencedata item based upon the progressive similarity criteria associated withthe pair. For example, in accordance with the progressive similaritycriteria, the PSE module 112 may be adapted to determine the number ofprogressive similarity scores that are to be calculated for a certainpair. According to one example, the progressive similarity criteria mayprovide a certain predefined number (two or more) setting forth theminimal number of progressive similarity scores that should becalculated for a pair comprised of the real-time CMS and a referencedata item, and the PSE module 112 may be adapted to determine whetherthe real-time CMS and a reference data item are similar or not based atleast upon the predefined number progressive similarity scores.According to some embodiments of the invention, the PSE module 112 maybe adapted to calculate the predefined number of progressive similarityscores for the real-time CMS and the reference data item, and todetermine that whether the real-time CMS and the reference data item aresimilar or not based on the predefined number of scores. However,according to further embodiments of the invention, rather than providinga fixed number of scores, the progressive similarity criteria may setforth rules and/or certain parameters in accordance with which thenumber of similarity scores that should be calculated is to bedetermined on-the-fly. According to still further embodiments, theprogressive similarity criteria may provide a minimal number ofprogressive similarity scores, and rules and/or parameters as to whenand how to extended the number of progressive similarity scores that areto be calculated on-the-fly, for example, in accordance with the resultsof the initial progressive similarity scores.

According to some embodiments of the invention, the progressivesimilarity criteria may provide one or more similarity threshold(s). Asimilarity threshold may be used for determining whether a certainprogressive similarity score (or scores) is indicative of a similaritybetween the portion of the real-time CMS data that is associated withthe instant with respect to which the score is calculated and thecorresponding portion of a reference data item. According to someembodiments of the invention, the PSE module 112 may apply thesimilarity threshold in respect of each progressive similarity scorecalculated or in respect of only some of the scores, and may considersome scores as a group. Another option is a similarity threshold that isdirected towards an average of some or all of the available progressivesimilarity scores. The application of the similarity threshold may beperformed in accordance with predefined rules or it may be dynamic andmay depend on various parameters, including, but not limited to, theprevious progressive similarity scores, the rate of media data exchangesduring the real-time CMS, etc. Furthermore, the similarity thresholdvalue may also be predefined, or in accordance with further embodimentsof the invention the similarity threshold value may be dynamicallydetermined based on various parameters made available during theprogress of the real-time CMS.

According to some embodiments of the invention, in addition to or as analternative to the similarity threshold, the progressive similaritycriteria may include a dissimilarity threshold(s). The dissimilaritythreshold may be used for determining whether a certain progressivesimilarity score (or scores) is indicative of dissimilarity between theportion of the real-time CMS data and a reference data item. Accordingto some embodiments of the invention, in case a certain reference dataitem is associated with a progressive similarity score (or scores) thatis below a dissimilarity threshold, the progressive similarityevaluation process may be terminated in respect of that reference dataitem.

It would be appreciated that, according to some embodiments of theinvention, different similarity/dissimilarity thresholds may be providedfor different scores, for example, a first similarity threshold may beassociated with a first score and a second score, whereas a secondsimilarity threshold may be associated with a third score, such that asthe real-time CMS progresses and more data becomes available, a higherlevel of similarity is required in order to consider a certainprogressive similarity score as being indicative of similarity. Inaccordance with another example, the lower the previous scoresassociated with a certain reference data item, the lower thedissimilarity threshold will be for the subsequent score calculated inrespect of that reference data item, and thus, a higher level ofsimilarity is needed as the real-time CMS progresses, if the referencedata item is to remain in consideration.

According to some embodiments of the invention, progressive similarityevaluation may further include determining whether the real-time CMS andthe reference data item or items are similar or not. The PSE module 112module may use the progressive similarity criteria to determine whethera reference data item(s) is similar to the real-time CMS. According tosome embodiments of the invention, according to the progressivesimilarity criteria, the PSE module 112 may be adapted to determine theprogressive similarity between the real-time CMS and a reference dataitem based upon two or more progressive similarity scores associatedwith the real-time CMS and the reference data item. According to theprogressive similarity criteria a pair comprised of a real-time CMS anda reference data item are to be considered similar if at all, or as analternative, at least a certain number of the progressive similarityscores calculated for that pair indicate that the pair is similar aswill be described in greater detail below. The evaluation of progressivesimilarity between a real-time CMS and a reference data item may takeplace after a certain number of progressive similarity scores (at leasttwo) is calculated for the pair or in accordance with furtherembodiments of the invention, a trigger for evaluating the progressivesimilarity between a pair comprised of a real-time CMS and a referencedata item may be determined on-the-fly, based upon various theprovisional results of the progressive similarity evaluation process orbased upon any other predefined parameters associated with theprogressive similarity evaluation process, such as for example, acertain amount of real-time CMS data being received.

According to some embodiments of the invention, in accordance with apossible similarity criteria that may be implemented by the PSE module112, the real-time CMS may be considered to be similar to a referencedata item when a certain number (two or more) of progressive similarityscores calculated for that pair is above a dissimilarity threshold,and/or if a certain number of progressive similarity scores calculatedfor that pair are above a similarity threshold. According to a furtherembodiments of the invention, in accordance with one possible similaritycriteria implemented by the PSE module 112, the real-time CMS may beconsidered to be similar to a reference data item, if a certain number(two or more) of progressive similarity scores calculated for that pairprovide an average progressive similarity score that is above adissimilarity threshold, and/or if a certain number of progressivesimilarity scores calculated for that pair provide an averageprogressive similarity score that is above a similarity threshold.

According to some embodiments of the invention, in accordance with thesimilarity criteria, in some cases where a progressive similarity scorecalculated for the real-time CMS and a certain reference data item isbelow a similarity threshold and/or in some cases where a progressivesimilarity score calculated for the real-time CMS and a certainreference data item is above a dissimilarity threshold, the PSE module112 may conclude that at least one more additional progressivesimilarity scores are needed in order to establish similarity or lackthereof, and accordingly, the PSE module 112 may continue theprogressive similarity evaluation process and may calculate anadditional progressive similarity score(s) for the real-time CMS and thereference data item. For example, in accordance with a similaritycriteria implemented by the PSE module 112, the PSE module 112 may beadapted to apply both a similarity threshold and a dissimilaritythreshold in respect of a certain progressive similarity score, and thePSE module 112 may be configured such that if a certain progressivesimilarity score falls between the similarity threshold and thedissimilarity threshold the progressive evaluation process should becontinued, and an additional progressive similarity score or scoresshould be calculated.

For example, in FIG. 2 and according to some embodiments of theinvention, according to the progressive similarity criteria implementedby the PSE module 112, the first progressive similarity score for eachof the available reference data items, and in the case of FIG. 2reference data items 204 and 206, is to be calculated in respect of afirst instant 232 during the progress or the real-time VoIP session 202.Based on the first progressive similarity score, reference data itemswhich are associated with a relatively low progressive similarity scoreare determined to be dissimilar and are withdrawn from furtherconsideration. For example, after the first progressive similarity scoreis calculated, the PSE module 112 may implement a progressivedissimilarity threshold that is designated for a first progressivesimilarity score to determine whether any of the reference data items204 and 206 is associated with a first progressive similarity score thatis below the predefined threshold. In FIG. 2, and in accordance withsome embodiments of the invention, following instant 232 and thecalculation of the first progressive similarity score, the PSE module112 may be adapted to implement a dissimilarity threshold with respectto the first progressive similarity score associated with each of thereference data items 204 and 206 participating in the progressivesimilarity evaluation process. The PSE module 112 may be configured todiscard any reference data item that is associated with a firstprogressive similarity score that falls below the dissimilaritythreshold. In the example shown in FIG. 2, following instant 232 andbased upon the progressive similarity score and a dissimilaritythreshold implemented in respect thereof, the PSE module 112 may beadapted to discard reference data item 206 from further consideration.Accordingly, the progressive similarity evaluation process in respect ofreference data item 206 may be discontinued beyond instant 232. In FIG.2 the progressive similarity score calculated in respect of instant 232for the real-time VoIP session 210 and reference data item 204 is abovethe dissimilarity threshold. Accordingly, the PSE module 112 may beconfigured to continue the progressive evaluation process in respect ofreference data item 204.

As mentioned above, according to embodiments of the invention,progressive similarity evaluation is based upon at least two progressivesimilarity scores. Accordingly, the PSE module 112 may be adapted tocontinue the progressive similarity evaluation process and may beadapted to calculate at least a second progressive similarity score inrespect of each of the remaining reference data items. For example, inFIG. 2 the PSE module 112 may be configured to calculate a secondprogressive similarity score in respect of instant 234 for each of theremaining (if any) reference data items, and in this case for referencedata item 204, and the real-time VoIP session 202. There are severalscenarios which may be implemented by the PSE module 112 after thesecond progressive similarity score is calculated. Examples of suchscenarios include, but are not limited to, any of the following and anycombination thereof:

a. Providing that both the first and the second progressive similarityscores are relatively high, the PSE module 112 may determine that thereal-time VoIP session 202 and the reference data item 204 should beconsidered similar and the real-time VoIP session 202 should be handledaccordingly, as will be described in further detail below.

b. Providing that one of the first two progressive similarity scores orthat one of the first two progressive similarity scores (and possibly aparticular one of the two) are relatively low, the PSE module 112 maydetermine that the real-time VoIP session 202 and the reference dataitem 204 are to be considered as being dissimilar and the real-time VoIPsession 202 should be handled accordingly; and

c. Providing that at least one (and possibly a particular one) of thefirst two progressive similarity scores is neither relatively high norrelatively low, or in accordance with a further example with one scoreis relatively high and the other is relatively low, the PSE module 112may decide to continue with the progressive similarity evaluationprocess with respect to the real-time VoIP session 202 and the referencedata item 204 and may calculate an additional progressive similarityscore(s) in respect of that pair. Then, further on during the progressof the real-time VoIP session 202 and after one or more additionalscores are calculated, the PSE module 112 module may apply theprogressive similarity criteria onto the scores and reattempt todetermine whether the real-time VoIP session 202 and the reference dataitem 204 are similar or not. In FIG. 2, following the calculation of thesecond progressive similarity score, and based on the result of one orboth of the two scores, the PSE module 112 may decide that an additionalscore is needed and may calculate a third progressive similarity scorebased upon the available VoIP data that is available at instant 236 anda corresponding portion of the reference data item 204. After the thirdprogressive similarity score is calculated, the PSE module 112 mayrevisit the progressive similarity criterion, and may reattempt todetermine whether the real-time CMS 202 and the reference data item 204are similar or dissimilar.

It should be appreciated that the above scenarios are provided by way ofillustration only, and that various other progressive similaritycriteria may be devised in accordance with some embodiments of theinvention.

According to some embodiments of the invention, once the PSE module 112detects an unwanted real-time CMS, for example, once the PSE module 112determines that a certain real-time CMS is similar or substantiallyidentical to a previous CMS, the PSE module 112 may be adapted toterminate the real-time CMS without delay. According to furtherembodiments of the invention, the PSE module 112 may terminate thereal-time CMS during its progress and as soon as it is determined thatthe real-time CMS and one or more reference data item(s) satisfy theprogressive similarity criteria. The PSE module 112 may be configured toidentify a real-time CMS as being unwanted based upon a unwanted CMSdetection criteria. According to an unwanted CMS detection criteria areal-time CMS may be identified as being unwanted if it is determinedthe real-time CMS and at least a reference data item or if the real-timeCMS and at least a certain number of reference data items comply with aprogressive similarity criteria. According to further embodiments of theinvention, an unwanted CMS detection criteria may provide additionalconditions which the real-time CMS and/or the reference data items mustcomply with in order for the real-time CMS to be considered unwanted.For example, according to an unwanted CMS detection criteria, areal-time CMS is considered to be unwanted if according to theprogressive similarity criteria there is at least a predefined number ofreference data items that are substantially identical to the real-timeCMS, and the similar reference data items are relatively recent. Itshould be noted however, that any reference data item that is notsufficiently recent may be filtered before the progressive similarityevaluation process in initiated in respect thereof.

It should be appreciated that, the progressive similarity evaluationprocess suggested in accordance with some embodiments of the invention,is directed towards detecting and blocking unwanted sessions based upona progressive measure of similarity in respect of previous CMSs, suchthat a real-time CMS is determined to be unwanted when there is at leastone or at least a predefined number of previous CMSs which are identicalor virtually identical to the present real-time CMS. In this context,some embodiments of the invention stipulate that authentic CMSs cannotbe identical or substantially identical to one another, especially if aplurality of CMS are identified as being virtually identical.Furthermore, even if the sessions are subjected to artificialmodifications to avoid identical sessions, the extent of themodifications is typically limited, especially if a relatively largenumber of synthetic sessions is generated. Some embodiments of thepresent invention suggest implementing appropriate progressivesimilarity criteria, so as to identify the artificially modifiedsessions as being similar or as being substantially identical.

It would be further appreciated, that real-time CMS traffic should notbe significantly delayed, and that otherwise the flow of conversationmay be significantly compromised. On the other hand, in order to preventor to reduce the harmful effects of unwanted CMS traffic, the unwantedCMS should be prevented if possible, or at least discontinued as soon aspossible. The progressive similarity evaluation process suggested inaccordance with some embodiments of the invention for detecting unwantedCMS traffic may offer a desirable tradeoff in the sense that it enablesrelatively fast and reliable detection of similarity between a real-timeCMS and a previous CMS. It would be further appreciated that accordingto some embodiments of the invention, if the similarity between thereal-time CMS and one or more previous CMSs (represented by one or morereference data items) progressive similarity may be established based ona relatively small amount of accumulated data and/or within a relativelyshort period of time since the start of the real-time CMS.

According to some embodiments of the invention, once the PSE module 112determines that a certain real-time CMS is unwanted, for example basedupon progressive similarity criteria and unwanted CMS detectioncriteria, the PSE module 112 may generate a CMS traffic control rule.The CMS traffic control rule may enable CMS traffic control. Accordingto some embodiments of the invention, the traffic control rule mayinclude data in respect of the real-time CMS which was determined to beunwanted. For example, according to some embodiments of the invention,after a certain real-time CMS is identified as being unwanted, a CMStraffic control rule may be generated which includes certain data inrespect of one or more characteristics of the unwanted CMS, such asmedia data (either explicitly or in some sort of compressed form, forexample) of the unwanted CMS, data in respect of certain signaling dataassociated with the unwanted CMS, etc.

The traffic control rule may enable a PSE module 112 to control futureCMS traffic. For example, the CMS traffic control rule may enable thePSE module 112 to identify similarity between a future real-time CMS andthe unwanted CMS (which at some future time shall be considered as aprevious CMS). In accordance with the CMS traffic control rule, areference data item may be generated and may be stored within thereference database 114 so as to enable a PSE module 112 moduleassociated with the reference database 114 to use the reference dataitem to detect unwanted CMS traffic (together with to any additionalreference data items). The CMS traffic control rule may be distributedthroughout the network so as to enable additional PSE modules to detectunwanted CMS traffic based on the CMS traffic control rule. It should beappreciated that recording data in respect of a CMS is not limited tounwanted CMSs, and rather a reference data item may be created inrespect of allowed CMSs as well. For example, initial CMSs which arepart of an unwanted bulk of CMS traffic may not be identified as beingunwanted according to a progressive similarity criteria implemented by acertain PSE module 112. It is only after a certain number of CMSs arereceived that enough reference data becomes available to enable the PSEmodule 112 to identify the subsequent CMSs as being unwanted and tocontrol the incoming CMS traffic accordingly.

According to further embodiments of the invention, either in addition oras an alternative to media data, a CMS traffic control rule may alsorelate to signaling data of the real-time CMS. The CMS traffic controlrule may include, for example, an IP address of an originator of thereal-time CMS, a domain name associated with the originator of theoriginator of the real-time CMS, a header of the real-time CMS, or anyother signaling data. Thus, the CMS control rule may provide varioussignaling data which may assist in detecting and controlling unwantedCMS data. The signaling data provided by a CMS traffic control rule maybe used to generate a “grey list” of CMS traffic which is associatedwith signaling data that is indicative of suspected CMS traffic. Forexample, in case a PSE module 112 identifies that a real-time CMSincludes certain signaling data, and in accordance with certain CMStraffic control rule, the PSE module 112 determines that the signalingdata is associated with suspected CMS traffic, as part of a progressivesimilarity evaluation process in respect of the real-time CMS, the PSEmodule 112 may adjust the progressive similarity evaluation process, forexample, so that similarity may be more quickly established (based onless media data). It would be appreciated that the PSE module 112 mayotherwise adjust the progressive similarity evaluation process when thePSE module 112 identifies that a real-time CMS includes certainsignaling data, and in accordance with a certain CMS traffic the PSEmodule 112 determines that the signaling data is associated withsuspected CMS traffic. According to further embodiments of theinvention, similar to the grey lists discussed above, the PSE module 112module may create “white lists” and/or “black lists” based on signalingdata of detected unwanted CMS traffic.

Reference is now made to FIG. 3, which is a block diagram of an optionalimplementation of a system for detecting unwanted conversational mediasessions, according to some embodiments of the invention. In FIG. 3, asystem for detecting unwanted CMS traffic 310 is implemented as part ofa CMS monitoring node 300. The CMS monitoring node 300 may be connectedto a network 306. The network 306 may also be the conduit forcommunications between one or more originators of CMS traffic 302 andone or more intended recipients 304, and in particular of real-time CMScommunications. According to some embodiments of the invention, the CMSmonitoring node 300 may be associated with one or more originators ofreal-time CMS traffic and/or the CMS monitoring node 300 may beassociated with one or more intended recipients of real-time CMStraffic. According to further embodiments of the invention, the CMSmonitoring node 300 may not be associated with any particularoriginator(s) or recipient(s). For example, the CMS monitoring node 300may be configured to monitor and evaluate CMS traffic randomly with noconnection to any particular originator or to any particular recipient.

In FIG. 3, the system for detecting unwanted CMS 310 may be attached tothe monitoring node 300 rather than to any particular intended recipient304 of CMS traffic. The monitoring node 300 may include atapping/interception module 316. The tapping module 316 may be adaptedto tap into real-time CMS traffic traversing the network. For example,the tapping module 316 may be adapted to tap into real-time CMScommunications traversing the network between an originator 302 of thereal-time CMS and a recipient of the real-time CMS traffic. Through thetap, the tapping module 316 may be adapted to obtain at least some ofthe real-time CMS data being exchanged. According to some embodiments ofthe invention, the tapping module 316 may be adapted to obtain thereal-time CMS data without substantially interfering with the real-timeCMS between the originator 302 and the intended recipient 304.

According to some embodiments of the invention, the real-time CMS datawhich was obtained through the tap may be fed to the PSE module 312. ThePSE module 312 may be adapted to implement the progressive similarityevaluation process described above in respect of the real-time CMS dataprovided by the tapping module 316. As part of the progressivesimilarity evaluation process, the PSE module 312 may be adapted tomeasure the similarity between the real-time CMS data accumulated duringthe progress of the real-time CMS and provided by the tapping module 316and one or more reference data items or portions of reference dataitems. As mentioned above, each reference data item may correspond to aprevious CMS. As also described above, the reference data items may bestored within a reference database 314, and the PSE module 312 mayobtain the data in respect of the reference data items from thereference database 314. In FIG. 3, and according to some embodiments ofthe invention, the reference database 314 is shown to be part of thesystem for detecting unwanted CMS 310 implemented on the monitoring node300. However, it would be appreciated that further embodiments of theinvention are not limited in this respect, and the reference database314 may be implemented elsewhere, for example, the reference database314 may be remotely implemented at a central location (servicing aplurality of PSE modules 312).

As mentioned above, the PSE module 312 may be adapted to determinewhether there are reference data items which are similar enough (asdetermined by one or more thresholds) to the real-time CMS, and inconjunction with the results of the progressive similarity evaluationprocess the PSE module 312 may apply a unwanted CMS detection criteriato determine whether the real-time CMS is unwanted. According to someembodiments of the invention, in case the real-time CMS is determined tobe unwanted, the system for detecting unwanted CMS 310 may be adapted toterminate the real-time CMS. It would be appreciated that theprogressive evaluation process may enable the system for detectingunwanted CMS 310 to terminate a real-time CMS, while the session is inprogress. For example, according to some embodiments of the invention,upon determining the real-time CMS is unwanted, the system 310 mayinstruct the intended recipient 304 to terminate the call (session).

Furthermore, in case the PSE module 312 determines that the real-timeCMS is unwanted, the PSE module 312 may generate a CMS traffic controlrule. As described in further detail above, the CMS traffic control rulemay include some characteristic or parameters which are associated withthe real-time CMS that has been determined to be unwanted, and mayenable a recipient of the rule to identify CMS traffic which includessaid characteristic or parameters or which include a characteristic orparameter which is correlated with the characteristic or parameterreferred to in the CMS traffic control rule and to handle the suspectedor unwanted CMS traffic accordingly. The CMS traffic control rule may bedistributed to various nodes throughout the network, to enable other PSEmodules or recipients of future CMS traffic to identify unwanted orsuspected CMS traffic. As mentioned above, a CMS traffic control rulemay including data in respect of signaling data associated with CMStraffic which has been identified as being unwanted and/or data inrespect of media data or signature corresponding to media associatedwith CMS traffic which has been identified as being unwanted.

According to further embodiments of the invention, CMS monitoring point300 may include an interception module either in addition or as analternative to the tapping module 316. The interception module may beadapted to intercept CMS traffic traversing the network. For example,the interception module may be adapted to monitor traffic traversing thenetwork or traversing a certain portion of the network, and uponidentification of a session initiation message(s) associated with areal-time CMS, the interception module may be adapted to intercept thesession initiation message(s). In accordance with one embodiment of theinvention, the interception module may be adapted to intercept thereal-time CMS session initiation messages before the messages arereceived at the intended recipient 304. The interception module may beadapted to establish a CMS call or a real-time CMS with the originator302 of the real-time CMS session initiation messages to inspect thereal-time CMS and to determine whether it is unwanted, as will bedescribed in further detail below.

According to some embodiments of the invention, upon identifying andintercepting the real-time CMS session initiation message(s), theinterception module may generate an appropriate response. As part ofresponding to the real-time session initiation messages, theinterception module may be adapted to process the session initiationmessage(s). Based on the processed data, and based on any relevant otherdata, the interception module may be adapted to generate a response tothe session initiation message in a manner to cause the originator 302of the session initiation messages to establish the real-time CMS withthe monitoring node 300 rather than with the intended recipient 304. Itwould be appreciated that according to some embodiments of theinvention, the interception module may be configured to utilize anypresently known or yet to be devised in the future method of techniquefor intercepting the real-time CMS data and in particular the real-timeCMS session initiation message(s). For instance, the real-time CMSpacket data traffic may be passed through a routing module that inaddition to plain routing, may also be configured to filter the datapackets according to some rules (for instance, certain CMS traffic), andmay pass an exact replica of the filtered traffic on a separate outputport to a monitoring module; the monitoring module may be equipped withsuitable logic for monitoring and analyzing CMS traffic, e.g. followingthe call setup and call control logic.

According to some embodiments of the invention, once a real-time CMS isestablished between the CMS monitoring node 300 and the originator 302,the PSE module 312 may be configured to begin the aforementionedprogressive similarity evaluation process based upon the media datareceived from the originator 302 during and as part of the real-timeCMS. According to some embodiments of the invention, if the initialmedia data that is provided by the originator 302 and that is receivedat the CMS monitoring node 300 is not enough to complete the progressivesimilarity evaluation process, the PSE module 312 in cooperation with amedia data simulator 318 may generate media data responses which areintended to entice the originator 302 to provide further media data, sothat the progressive similarity evaluation process may be concluded.According to some embodiments of the invention, as part of generating amedia data response, the media data simulator 318 may be adapted toprocess the incoming media data and may provide in response pre-recordedmedia data. The media data provided by the media data simulator 318 maybe intended to provide a logical response to the originator initialmedia data communication. However, further embodiments of the inventionare not limited in this respect, rather according to some embodiments ofthe invention, the media data simulator 318 may divulge to theoriginator 302 certain details in connection with the interception andmay request the originator 302 to make a certain statement which may beused as part of the progressive similarity evaluation process. The mediadata simulator 318 may be adapted to utilize various media processingalgorithms and various media generation algorithms to process theincoming media data and to generate, on-the-fly, an appropriateresponse. Various speech processing and speech reconstruction and/orimage processing and image reconstruction or any other media processingand/or media generation techniques may be utilized by the media datasimulator 318.

Once the PSE module 312 has enough media data to determine whether thereal-time CMS is similar to one or more of the reference data items, thePSE module 312 may use the unwanted CMS detection criteria to determinewhether the originator's 302 intention was to establish an unwantedreal-time CMS with the intended recipient 304. If the PSE module 312determines, based on the intercepted media data that the real-time CMSwhich the originator 302 was seeking to establish is an unwanted CMS,the CMS monitoring node 300 may block the real-time CMS. Blocking thereal-time CMS may include any one of the following and any combinationthereof: discontinuing or dropping the call at the intermediary node's300 end; blocking the session from arriving at the intended recipientand not allowing the call to proceed to its intended recipient;diverting the real-time CMS to an alternative address, for example,diverting the call to a voice/multimedia mailbox, etc. According tofurther embodiments of the invention, either in addition or as analternative to blocking or otherwise handling the real-time CMS whichhas been determined to be unwanted, the PSE module 312 may be adapted togenerate one or more CMS traffic control rules, as was described ingreater detail above.

The PSE module 312 may also be adapted to update the reference database314 with data about the real-time CMS, so as to enable futureimplementation of the progressive similarity evaluation process inrespect of the real-time CMS (which will be considered as a previousCMS). According to some embodiments of the invention, the module 312 maybe adapted to record data in respect of the real-time CMS within thereference database 314 regardless of the results of the unwanted CMSdetection process.

If however, the PSE module 312 decides that the real-time CMS is notunwanted, for example, based on the unwanted CMS detection criteria, thePSE module 312 may be adapted to establish a real-time CMS between theoriginator 302 and the intended recipient 304. According to someembodiments of the invention, the real-time session between theoriginator 302 and the intended recipient 304 may be established throughthe intermediary node 300. However, according to further embodiments ofthe invention, the intermediary node 300 may only be involved inestablishing the session between the parties but may not be aparticipant itself. According to further embodiments of the invention,the unwanted CMS detection process (including the progressive similarityevaluation process) may be transparent to the intended recipient.However, according to further embodiments of the invention, theintermediary node 300 may be adapted to inform the intended recipient304 of the unwanted CMS detection process. As part of updating theintended recipient 304 the intermediary node 300 may provide theintended recipient 304 with details of the results of the unwanted CMSdetection process with respect to the real-time CMS.

According to further aspects of the present invention there is provideda method of detecting unwanted CMS traffic which includes obtaining asequence of significant attributes directly from a bit-streamcorresponding to a real-time CMS, and evaluating similarity between thesequence of significant attributes associated with the real-time CMS anda reference data item corresponding to a sequence of significantattributes of a bit-stream associated with a previous CMS. The directbit-stream similarity evaluation process may be applied onto the mediaportion of the real-time CMS. Also, according to a further embodiment ofthe invention, the reference data item may include data corresponding tosignificant attributes taken or extracted from a bit-streamcorresponding to a media portion of a previous CMS. According to someembodiments of the invention, the direct bit-stream similarityevaluation process does not require the real-time CMS media data beingdecoded and may be applied to the encoded data stream.

It should be appreciated that according to some embodiments of theinvention, the direct bit-stream similarity evaluation process, whichwill be described in further detail below, may be implemented as part ofthe progressive similarity evaluation process. For example, as part of aprogressive similarity evaluation process, one or more progressivesimilarity scores may be calculated using the direct bit-streamsimilarity evaluation process according to some embodiments of theinvention. The application of the direct bit-stream similarityevaluation process for calculating a progressive similarity score mayinclude, for example, obtaining a sequence of significant attributesdirectly from a bit-stream corresponding to real-time CMS dataaccumulated up to a certain instant during the progress of the real-timeCMS, and calculating a progressive similarity score based upon asimilarity between the obtained sequence of significant attributes and areference data item corresponding to a sequence of significantattributes of a bit-stream associated with a previous CMS or with someportion thereof. The direct bit-stream similarity evaluation process maybe repeated in respect of different instants during the progress of thereal-time CMS so as to enable progressive similarity evaluation betweenthe real-time CMS and the reference data based upon the two or moreprogressive similarity scores.

However, it should be appreciated, that according to further embodimentsof the invention, the direct bit-stream similarity evaluation processmay be implemented by a system for detecting unwanted CMS independentlyfrom any other similarity evaluation process including the progressivesimilarity evaluation process. For example, the direct bit-streamsimilarity evaluation process may be applied in respect of a certainamount of accumulated real-time CMS bit stream data, and the conclusionwith regard to the real-time CMS being unwanted or not may be arrived atbased on a single application of the similarity measure rather thanbeing based upon a repeated progressive application as is suggested bythe progressive similarity evaluation process.

Reference is now made to FIG. 4, which is a simplified block diagramillustration of certain implementations of a system configured forimplementing a direct bit-stream similarity evaluation process fordetecting unwanted CMS traffic. In FIG. 4, and according to someembodiments of the invention, the system for detecting unwanted CMStraffic 410 may be configured to implement a direct bit-streamsimilarity evaluation process as part of detecting unwanted CMS traffic.The direct bit-stream similarity evaluation process shall be describedin greater detail below. The system for detecting unwanted CMS traffic410 may be adapted to implement the direct bit-stream similarityevaluation process either in conjunction with the progressive similarityevaluation process described above, for example, for the purpose ofcalculating one or more progressive similarity scores, or as analternative and in accordance with further embodiments of the invention,the direct bit-stream similarity evaluation process may be an autonomoussimilarity evaluation process utilized by the system 410 for detectingunwanted CMS traffic. In particular, the similarity evaluation processimplemented by the system 410 shown in FIG. 4 may be applied in respectof a specific instant during the progress of the CMS or in respect ofthe entire real-time CMS media data. Further details in respect of thedirect bit-stream similarity evaluation process in accordance with someembodiments of the invention shall be provided below.

Returning back to FIG. 4, the system for detecting unwanted CMS 410 mayinclude a bit-stream similarity evaluation module 412 and a referencedatabase 414. The bit-stream similarity evaluation module 412 may beadapted to detect real-time CMS traffic, for example, by detecting CMSsignaling data or CMS initiation messages or by detecting real-time CMSmedia data. In one implementation of the similarity evaluation module412, a sniffer (not shown) may be employed to detect and capture CMSdata transmitted on the network. Upon detection of the real-time CMStraffic, the bit-stream similarity evaluation module 412 may implement adirect bit-stream evaluation process to determine whether the detectedreal-time CMS is unwanted. In FIG. 4, and according to some embodimentsof the invention, the system for detecting unwanted CMS 410 is shown tobe attached to a specific intended recipient 404 of a real-time CMS.However, according to further embodiments of the invention, the systemfor detecting unwanted CMS 410 may be associated with any other nodewithin the network or with any other group of nodes, such as, with anynode which belongs to a certain network domain or in accordance withstill further embodiments of the invention, the system for detectingunwanted CMS 410 may not necessarily be attached to any particular nodewithin the network, as for example, was described with reference to FIG.3.

According to some embodiments of the invention, the reference database414 may include one and typically more (i.e. a plurality) of referencedata items. Each reference data item may correspond to a previous CMS orto a portion of a previous CMS. According to further embodiments of theinvention, at least some of the reference data items within thereference database 414 may each include or may be associated with asequence of significant attributes taken directly from the bit-stream ofa previous CMS. It would be appreciated that a reference data item whichincludes a sequence of significant attributes derived from thebit-stream of a previous CMS may be obtained from the previous CMS inits encoded form and does not require the previous CMS to be decoded tothat end. It should also be appreciated, that according to someembodiments of the invention, by including in respect of a previous CMSonly a sequence of significant attributes taken directly from the(encoded and possibly compressed) bit-stream of a previous CMS ratherthan from the decoded media data of the previous CMS, a significantreduction with respect to the amount of storage space needed to storethe reference data item may be achieved. As mentioned above, a previousCMS as used herein, unless specifically stated otherwise, relates to anyCMS traffic traversing the network and intercepted or otherwiseobtained. Thus, the reference data items are based upon actual CMStraffic, rather than being some sort of a simulation of CMS traffic.

According to some embodiments of the invention, as part of implementingthe similarity evaluation process, the bit-stream similarity evaluationmodule 412 may be adapted to obtain a sequence of significant attributesdirectly from a bit-stream corresponding to the real-time CMS. Referenceis now additionally made to FIG. 5, which is a symbolic representationof a time ordered sequence of significant attributes obtained from abit-stream corresponding to a portion of a real-time CMS and ofreference data items which include (each) data in respect of significantattributes obtained from a bit-stream corresponding to a portion of aprevious CMS, according to some embodiments of the invention. In FIG. 5,the topmost sequence of significant attributes 502 is obtained from abit-stream corresponding to a portion of a real-time CMS. The referencedata items 504 and 506 each includes data in respect of significantattributes obtained from a bit-stream corresponding to a portion of aprevious CMS. By way of example, in FIG. 5 the sequence of significantattributes 502 captured from the bit-stream that corresponds to thereal-time CMS, is comprised of a set of gain values which when decodedprovide some of the data needed to represent the real-time CMS mediadata to a user, for example. Further by way of example, each gain valuein the sequence corresponds to a sequence of three bits within thebit-stream which denote its value (between 0 and 7). Similarly thereference data items 504 and 506 each comprise data in respect of a setof gain values associated with a previous CMS. Examples of significantattributes which may be monitored as part of the direct bit-streamsimilarity evaluation process may include, but are not limited to thefollowing: gain parameters and in particular gain parameters of theadaptive and/or the fixed codebooks, spectral parameters and inparticular spectral parameters coded as LSP (Line Spectral Pair)parameters, and any combination thereof. Furthermore, it would beappreciated that some forms of CMS or some CMS protocols may include aspart of the bit-stream more than one set of gain values or more than oneset of any other type of data or value, and that according to someembodiments of the invention, the direct bit-stream similarityevaluation process may relate to only one set of values or to more thanone set.

The bit-stream similarity evaluation module 412 may be adapted toevaluate similarity between the sequence of significant attributes 502and the reference data item 504 and 506. According to some embodimentsof the invention, as part of the direct bit-stream similarity evaluationprocess, the bit-stream similarity evaluation module 412 may be adaptedto compare the sequence of significant attributes 502 obtained from abit-stream corresponding to a portion of a real-time CMS with each ofthe reference data items 504 and 506.

The bit-stream similarity evaluation module 412 may be adapted tocompare the sequence of significant attributes 502 obtained from abit-stream corresponding to a portion of a real-time CMS with everyavailable reference data item. However, according to further embodimentsof the invention, the totality of reference data items may be subjectedto preliminary elimination, so that the similarity evaluation processmay be carried out only in respect of the reference data items whichhave not been eliminated during the preliminary process. The preliminaryelimination screening process may be implemented in order to filter outreference data items which are not likely to result in high similarityin respect of the real-time CMS. According to some embodiments of theinvention, the preliminary elimination process may be configured to be arelatively straightforward process. It would be appreciated that byintroducing a relatively straightforward preliminary elimination processinto the similarity evaluation process, a more stream-lined process maybe achieved, and that by focusing the portion of the process whichinvolves relatively complex comparison computations onto a more limitedset of reference data items, overall complexity may be reduced.

According to some embodiments of the invention, the preliminaryelimination process may include certain criteria which may be used forfiltering the reference data items in respect of which the similarityevaluation process is to be discontinued. According to some embodimentsof the invention, the criteria may relate to certain signaling datawhich may be associated with the reference data items. For example,according to one embodiment of the invention, one or more reference dataitems may include signaling data associated with the previous CMS withwhich the reference data item corresponds, and as part of thepreliminary elimination process, the bit-stream similarity evaluationmodule 412 may be adapted to eliminate reference data items based uponsignaling data included therein. For illustration, in accordance withone implementation of the system for detecting unwanted CMS 410, upondetecting a real-time CMS, the evaluation module 412 may be configuredto capture the signaling data of the real-time CMS and may use that datato eliminate unrelated reference data items from being evaluated forsimilarity. For example, in case the captured signaling data is an IPaddress of the originator 402, the bit-stream similarity evaluationmodule 412 may implement (as part of the similarity evaluation process)a preliminary elimination process, and as a result of the preliminaryelimination process only reference data items which include data inrespect of an IP address that is within the same network domain as theoriginator's 402 IP address will be further considered for similarity aspart of the similarity evaluation process.

According to some embodiments of the invention, the bit-streamsimilarity evaluation module 412 may implement a similarity threshold.The similarity threshold may be used for determining whether a real-timeCMS and a certain reference data item(s) should be considered as beingsimilar. The similarity threshold implemented by the bit-streamsimilarity evaluation module 412 may relate to the level of similaritybetween a sequence of significant attributes derived from the bit-streamwhich corresponds to the real-time CMS and data in respect of a sequenceof significant attributes associated with a bit-stream which correspondsto a previous CMS as provided by a reference data item. The similaritythreshold may be applied in respect of a plurality of reference dataitems to determine which ones, if any, provide a sufficiently highsimilarity score when compared with the data associated with thereal-time CMS. For example, in accordance with one embodiment of theinvention, in accordance with a similarity threshold, a sequence ofsignificant attributes associated with the real-time CMS and a certainreference data item may be considered to be similar, if the similaritybetween the two sets of values is above a certain level.

According to some embodiments of the invention, the bit-streamsimilarity evaluation module 412 may be adapted to implement an unwantedCMS detection criteria on top of the similarity threshold to determinewhether a real-time CMS is unwanted. Discussions of the relationshipbetween an unwanted CMS detection criteria and the similarity thresholdwere provided above, in connection with the progressive similarityevaluation approach. However, it should be appreciated that therelationship between the unwanted CMS detection criteria and thesimilarity threshold(s) may be otherwise defined and characterized, forexample, in accordance with the unwanted CMS detection criteria and oneor more tolerance components may be implemented by the system fordetecting unwanted CMS traffic 410 on top of or independently from thesimilarity threshold(s). In accordance with other embodiments of theinvention, the system for detecting unwanted CMS traffic 410 may use thesimilarity threshold as the criteria for detecting unwanted CMS traffic,without any other further criteria being used.

According to some embodiments of the invention, the unwanted CMSdetection process may incorporate one or more tolerance components. Thetolerance components may allow for controlled inconsistencies betweenthe real-time CMS and the reference data items, so that controlledsimilarity rather than absolute identity is the criterion for detectingunwanted CMS traffic. The tolerance components may be implemented aspart of the similarity threshold employed by the similarity evaluationmodule 412. For example, one or more tolerance components, possibly inconjunction with other considerations, may be used to determine thelevel of similarity that is to be required in accordance with thesimilarity threshold for certain data in respect of a real-time and areference data item to be considered as being similar. According tofurther embodiments of the invention, a tolerance component may beimplemented across the entire range of reference data items, or inaccordance with an alternative embodiment, in respect of only specificreference data item(s). According to a further embodiment of theinvention, tolerance components may also be applied to control for acertain inconsistency between the data in respect of the real-time CMSand a reference data, so that the effect of that inconsistency iseliminated or decreased under certain circumstances. Some examples oftolerance values may include tolerance values which are intended tocontrol for or account to inconsistencies which are associated with oneor more of the following: packet loss over the data network, constantdelay and delay variation (jitter) between sessions, etc.

The similarity evaluation module 412 may be adapted to implement theunwanted CMS detection criteria during the progress of the real-time CMSand in case it is determined that the real-time CMS is unwanted, thesession may be terminated, and any further incoming communication, forexample, from the originator 402 in connection with the real-time CMSmay be rejected. However, according to further embodiments of theinvention, the similarity evaluation module 412 may implement theunwanted CMS detection criteria only after the real-time CMS iscompleted and may not influence the progress of the real-time CMS.According to some embodiments of the invention, if it is determined thata real-time CMS is unwanted (for example, during the progress of thereal-time CMS, or in accordance with another example, after thereal-time is complete), the system for detecting unwanted CMS 410 may beadapted to generate one or more CMS traffic control rules. The CMStraffic control rules may be used to control future CMS traffic. Asmentioned above, the CMS traffic control rules may be distributed tovarious nodes located throughout the network 406 to enable the nodes inreceipt of the CMS control rules to control CMS traffic associated withthose nodes, for example, to control CMS traffic whose intendedrecipient is that node. A more detailed description of various CMStraffic control rules was provided above with reference to theprogressive similarity evaluation approach and is applicable mutatismutandis to the direct bit-stream approach to evaluating similaritybetween data in respect of a real-time CMS and data in respect of aprevious CMS.

Turning now to FIG. 6, there is shown a simplified block diagramillustration of certain implementations of a system configured forimplementing a packet arrival time similarity evaluation process fordetecting unwanted CMS traffic. In FIG. 6, and according to someembodiments of the invention, the system for detecting unwanted CMStraffic 610 may be configured to implement a packet arrival timesimilarity evaluation process as part of detecting unwanted CMS traffic.The packet arrival time similarity evaluation process shall be describedin greater detail below. The system for detecting unwanted CMS traffic610 may be adapted to implement the packet arrival time similarityevaluation process either in conjunction with the progressive similarityevaluation process described above, for example, for the purpose ofcalculating one or more progressive similarity scores, or as analternative and in accordance with further embodiments of the invention,the packet arrival time similarity evaluation process may be anautonomous similarity evaluation process utilized by the system 610 fordetecting unwanted CMS traffic. In particular, the similarity evaluationprocess implemented by the system 610 shown in FIG. 6 may be applied inrespect of a specific (one) instant during the progress of the CMS or inrespect of the entire real-time CMS media data. Further details inrespect of the packet arrival time similarity evaluation process inaccordance with some embodiments of the invention shall be providedbelow.

Returning back to FIG. 6, the system for detecting unwanted CMS 610 mayinclude a packet arrival similarity evaluation module 612 and areference database 614. The packet arrival similarity evaluation module612 may be adapted to detect real-time CMS traffic, for example, bydetecting CMS signaling data or CMS initiation messages or by detectingreal-time CMS media data. In one implementation of the similarityevaluation module 612, a sniffer (not shown) may be employed to detectand capture CMS data transmitted on the network. Upon detection of thereal-time CMS traffic, the packet arrival similarity evaluation module612 may implement a packet arrival similarity evaluation process todetermine whether the detected real-time CMS is unwanted. In FIG. 6, andaccording to some embodiments of the invention, the system for detectingunwanted CMS 610 is shown to be attached to a specific intendedrecipient 604 of a real-time CMS. However, according to furtherembodiments of the invention, the system for detecting unwanted CMS 610may be associated with any other node within the network or with anyother group of nodes, such as, with any node which belongs to a certainnetwork domain or in accordance with still further embodiments of theinvention, the system for detecting unwanted CMS 610 may not necessarilybe attached to any particular node within the network, as for example,was described with reference to FIG. 3.

According to some embodiments of the invention, as part of implementingthe similarity evaluation process, the packet arrival similarityevaluation module 612 may be adapted to obtain at least a sequence ofpacket arrival times in respect of a real-time CMS. According to furtherembodiments of the invention, the packet arrival similarity evaluationmodule 612 may be adapted to obtain the packet arrival data directlyfrom the bit-stream which corresponds to the real-time CMS. The packetarrival data may include a sequence of packet inter-arrival times.Packet inter-arrival time can be defined as the amount of time betweenan arrival of a packet and the arrival of the next packet or as theamount of time between the arrival of a packet and the arrival of theprevious packet. The sequence of packet arrival times or inter-arrivaltimes may be obtained by the packet arrival similarity evaluation module612 through direct monitoring of the bit-stream which corresponds to thereal-time CMS. It should be appreciated that any known in the present oryet to be devised in the future method or technique that is suitable fortiming the packet arrival times may be utilized as part of someembodiments of the invention to enable the monitoring and recording ofthe packet arrival or packet inter-arrival times.

According to some embodiments of the invention, the reference database614 may include one and typically more (i.e. a plurality) of referencedata items. Each reference data item may correspond to a previous CMS orto a portion of a previous CMS. According to further embodiments of theinvention, at least some of the reference data items within thereference database 614 may include or may be associated with at least asequence of packet arrival times corresponding to a previous CMS. Inaccordance with a further embodiment of the invention, one or more ofthe reference data items may include data in respect of packetinter-arrival times corresponding to a previous CMS. It would beappreciated that a reference data item which includes a sequence ofpacket arrival time or packet inter-arrival time may be created basedupon data derived directly from the bit-stream of a previous CMS. Thereference data maybe generated based upon data obtained from theprevious CMS in its encoded form and the procurement of the referencedata may not require the previous CMS to be decoded to that end. Itshould also be appreciated, that according to some embodiments of theinvention, by including in respect of a previous CMS only a sequencepacket, arrival times which are taken directly from the (encoded andpossibly compressed) bit-stream of a previous CMS rather than from thedecoded media data of the previous CMS, a significant reduction withrespect to the amount of storage space needed to store the referencedata item may be achieved. As mentioned above, a previous CMS as usedherein, unless specifically stated otherwise, relates to any CMS traffictraversing the network and intercepted or otherwise obtained. Thus, thereference data items are based upon actual CMS traffic, rather thanbeing some sort of a locally simulated CMS data.

Reference is now additionally made to FIG. 7, which is a symbolicrepresentation of a stream of data packets corresponding to a portion ofa real-time CMS and of reference data items which include (each) astream of data packets corresponding to at least a portion of a previousCMS, according to some embodiments of the invention. In FIG. 7, thestream of data packets 702 corresponds to at least a portion of areal-time CMS. As mentioned above, the packet arrival similarityevaluation module 612 may be adapted to obtain at least packet arrivaldata in respect of a real-time CMS. The packet arrival similarityevaluation module 612 may be adapted to obtain the packet arrival datadirectly from the bit-stream (or stream of data packets) 702 whichcorresponds to the real-time CMS. In FIG. 7 and according to someembodiments of the invention, the packet arrival similarity evaluationmodule 612 is adapted to generate the packet arrival data by measuringthe time intervals between the time of arrival of each packet in thestream of packets 702 being monitored and the time of arrival of thenext packet in stream. Each of the reference data items 704 and 706shown in FIG. 7 may include at least data in respect of packet arrivaltimes obtained in respect of a previous CMS. Each of the reference dataitems 704 and 706 may be generated based upon data obtained directlyfrom a bit-stream (or stream of data packets) corresponding to at leasta portion of a previous CMS.

The packet arrival similarity evaluation module 612 may be adapted toevaluate similarity between the packet arrival data corresponding to thestream of data packets 702 which corresponds to at least a portion of areal-time CMS and the reference data items 704 and 706. The packetarrival similarity evaluation process may include comparing the packetarrival data associated with the real-time CMS with the packet arrivaldata associated with the previous CMSs as provided by the reference dataitems 704 and 706. According to further embodiments of the invention,the packet arrival similarity evaluation module 612 may be adapted toevaluate similarity between the real-time CMS and the reference dataitems based upon a comparison of packet inter-arrival times obtainedfrom the stream of data packets 702 which corresponds to at least aportion of a real-time CMS and packet-inter-arrival data provided by thereference data items 704 and 706, which as mentioned above, may be basedupon streams of packets associated with previous CMSs.

As described in greater detail above with reference to the directbit-stream approach to similarity evaluation, as part of the similarityevaluation process, and in particular as part of the packet arrivalsimilarity evaluation process, the initial set of reference data itemsmay be subject to a preliminary elimination process, so that the processof comparing packet arrival data is carried out in respect to a morefocused set of reference data items. As is also mentioned above, thenarrowed down set of reference data items may be achieved through ascreening process that may be based upon a search for a certaincharacteristic that is associated with the real-time CMS within thereference data items. The characteristic upon which the screeningprocess may be based may be selected such that the identificationthereof within a reference data item is relatively straightforward sothat compliance (or non-compliance) may be rather easily established.

According to some embodiments of the invention, the packet arrivalsimilarity evaluation module 612 may implement a similarity threshold.The similarity threshold may be used for determining whether a real-timeCMS and a certain reference data item(s) should be considered as beingsimilar. The similarity threshold implemented by the packet arrivalsimilarity evaluation module 612 may relate to the level of similaritybetween a sequence of packet arrival times associated with the real-timeCMS and data in respect of a sequence of packet arrival times associatedwith a previous CMS as provided by a reference data item. According tofurther embodiments of the invention, the similarity threshold mayrelate to the level of similarity between a sequence of packetinter-arrival times associated with the real-time CMS and data inrespect of a sequence of packet inter-arrival times associated with aprevious CMS as provided by a reference data item. The similaritythreshold may be applied in respect of a plurality of reference dataitems to determine which ones, if any, provide a sufficiently highsimilarity score when compared with the data associated with thereal-time CMS. For example, in accordance with one embodiment of theinvention, in accordance with a similarity threshold, a sequence ofpacket arrival times associated with the real-time CMS and a certainreference data item may be considered to be similar, if the similaritybetween the two sets of values is above a certain level.

According to further embodiments of the invention, the similaritythreshold may further relate to the size of packets in the packetstream. The similarity evaluation module 612 may be adapted to obtaindata with respect to the size of packets within a stream of packetsassociated with real-time CMS. The data in respect size of packets maybe provided in the form of a sequence of packet sizes. The size ofpackets may be represented, for example, by the number of data bitsincluded as part of each packet. However, it should be noted, thatcertain data bits may be disregarded when determining the size of apacket, such as for example, metadata packets, and only content (ormedia) data may be considered. The data with respect to the size of thepackets may be obtained by the similarity evaluation module 612 throughdirect monitoring of the bit-stream (or packet stream) corresponding tothe real-time CMS. It should be appreciated that any known in thepresent or yet to be devised in the future method or technique that issuitable for sizing the packets may be utilized as part of someembodiments of the invention to enable the monitoring and recording ofthe packet sizes.

According to further embodiments of the invention, at least some of thereference data items within the reference database 614 may include datain respect of the size of packets within a packet stream correspondingto a previous CMS. In accordance with a further embodiment of theinvention, one or more of the reference data items may include data inrespect of a sequence of packet sizes within a packet streamcorresponding to a previous CMS. The reference data may be created basedupon data obtained from the previous CMS in its encoded form and theprocurement of the reference data may not require the previous CMS to bedecoded to that end.

According to some embodiments of the invention, the similarityevaluation module 612 may be adapted to obtain the data with respect tothe size of the packets in addition to (obtaining) the sequence ofpacket arrival times associated with the stream of packets correspondingto the real-time CMS. Furthermore, some of the reference data items mayinclude, in addition to the sequence of packet arrival times associatedwith a packet stream corresponding to a previous CMS, data with respectto the size of the packets within the stream of packets corresponding tothe previous CMS.

According to some embodiments of the invention, the similarityevaluation module 612 may be adapted to compare the sequence of packetarrival times associated with the real-time CMS with the data providedby a reference data item in respect of the packet arrival timesassociated with a previous CMS, and separately compare the data withrespect to the size of packets associated with the real-time CMS withthe data provided by a reference data item with respect to packet sizesassociated with a previous CMS. The similarity evaluation module 612 mayinclude a plurality of similarity thresholds to determine whether theresults of at least the packet arrival times comparison and the packetsize comparison are indicative of similarity or not. However, accordingto further embodiments of the invention, as part of the similarityevaluation process, the similarity evaluation module 612 may beconfigured to apply a transformation function to the set of valuesassociated with the real-time CMS and the set of values provided by areference data item and may compare the results of the transformationrather than performing multiple and discrete sets of calculation. Anexample of a suitable transformation function may include, but is notlimited to, a transformation function which provides an empiricaldistribution of packet inter-arrival times and packet sizes.

According to some embodiments of the invention, the similarityevaluation module 612 may be adapted to implement an unwanted CMSdetection criteria on top of the similarity threshold(s) to determinewhether a real-time CMS is unwanted. Discussions of the relationshipbetween an unwanted CMS detection criterion and the similarity thresholdwere provided above, in connection with the progressive similarityevaluation approach. However, it should be appreciated that therelationship between the unwanted CMS detection criteria and thesimilarity threshold(s) may be otherwise defined and characterized, forexample, in accordance with the unwanted CMS detection criteria one ormore tolerance components may be implemented by the system for detectingunwanted CMS traffic 610 on top of or independently from the similaritythreshold(s). In accordance with other embodiments of the invention, thesystem for detecting unwanted CMS traffic 610 may use the similaritythreshold as the criteria for detecting unwanted CMS traffic, withoutany other further criteria being used.

The similarity evaluation module 612 may be adapted to implement theunwanted CMS detection criteria during the progress of the real-time CMSand in case it is determined that the real-time CMS is unwanted, thesession may be terminated, and any further incoming communication, forexample, from the originator 602 in connection with the real-time CMSmay be rejected. However, according to further embodiments of theinvention, the similarity evaluation module 612 may implement theunwanted CMS detection criteria only after the real-time CMS iscompleted and may not influence the progress of the real-time CMS.According to some embodiments of the invention, if it is determined thata real-time CMS is unwanted (for example, during the progress of thereal-time CMS, or in accordance with another example, after thereal-time is complete), the system for detecting unwanted CMS 610 may beadapted to generate one or more CMS traffic control rules. The CMStraffic control rules may be used to control future CMS traffic. Asmentioned above, the CMS traffic control rules may be distributed tovarious nodes located throughout the network 606 to enable the nodes inreceipt of the CMS control rules to control CMS traffic associated withthose nodes, for example, to control CMS traffic whose intendedrecipient is that node. A more detailed description of various CMStraffic control rules was provided above with reference to theprogressive similarity evaluation approach and is applicable mutatismutandis to the packet arrival times approach (with or without theadditional data in respect of the packet sizes) to evaluating similaritybetween data in respect of a real-time CMS and data in respect of aprevious CMS.

It should be appreciated that some of the discussions above made withreference to specific aspects of the invention, such as for example,with reference to the progressive similarity evaluation approach towardsdetecting unwanted CMS traffic and/or with reference to the directbit-stream similarity evaluation approach towards detecting unwanted CMStraffic, may be included, implemented or applied as part of one or moreof the other approaches towards detecting unwanted CMS traffic which aredescribed herein as being part of further aspects of the invention.Thus, unless explicitly stated otherwise or if it is apparent from thetext that the intention of the applicant is to the contrary, anydiscussion made throughout the specification and should be regarded asbeing part of mutatis mutandis any of the other aspects of the inventiondescribed in the present specification.

Reference is now made to a further aspect of the invention. According tosome embodiments of the invention, a method of detecting unwanted CMStraffic may include utilizing a fake conversational client. The fakeconversational client may be adapted to cause an originator of real-timeCMS data to setup and initiate a real-time CMS with the fakeconversational client. According to some embodiments of the invention,the fake conversational client may be adapted to generate a referencedata item based upon at least a media portion of the incoming real-timeCMS. The fake conversation client may be further configured to publishthe reference data item in a manner to enable a client in receipt of thereference data item to control incoming real-time CMS traffic based upona similarity between the incoming real-time CMS data and the referencedata item.

Reference is now made to FIG. 8 which is a block diagram illustration ofa system for enabling detection of unwanted CMS traffic which includes afake CMS client, according to some embodiments of the invention. Inaccordance with some embodiments of the invention, a system for enablingdetection of unwanted CMS traffic 810 may be implemented as part of ormay be associated with a fake CMS client 820. The fake CMS client 820may be adapted to cause an originator 802 of real-time CMS data tosetup, initiate and conduct a real-time CMS with the fake CMS client820. As will be described in further detail below, the fake CMS client820 may be adapted to decode incoming real-time CMS data. According tofurther embodiments of the invention, the fake CMS client 820 may befurther adapted to generate synthetic CMS data, for example, in responseto real-time CMS data received at the fake CMS client 820.

The fake CMS client 820 may include or may be associated with areference data generator 822. The reference data generator 822 may beused to generate reference data items. The reference data generator 822may be adapted to generate a reference data item based upon at least themedia data or some portion thereof received at the fake CMS client 820as part of a real-time CMS. The fake CMS client 820 may further includeor may be associated with a reference data publisher 826. The referencedata publisher 826 may be adapted to publish a reference data itemgenerated by the reference data generator 822. The reference datapublisher 826 may be configured to transmit, including by way ofbroadcast or multicast, a reference data item to one or more clientsover the network 806, so that the reference data can be made availableto one or more clients 804, thereby enabling the clients 804 in receiptof the reference data item to use the reference data item to controlfuture CMS traffic. According to some embodiments of the invention thereference data publisher 826 may be configured to provide a referencedata item generated at the fake CMS client 820 to one or more clientswhich are subscribers of the fake CMS client 820.

According to some embodiments of the invention, the fake CMS client 820may include or may be associated with a CMS interface 824. The CMSinterface 824 may be configured to enable the setup of the real-time CMSon the fake CMS client 820 end. The CMS interface 824 may be furtheradapted to control certain aspects of the real-time CMS while it is inprogress. The CMS interface 824 may be adapted to receive the signalingdata associated with the real-time CMS and may be adapted to generateany CMS signaling data necessary for setting up and/or for managing thereal-time CMS. The CMS interface 824 may be adapted to interface varioustypes of real-time CMS, including but not limited to VoIP sessions,video sessions, mixed voice/audio/real-time text chat, etc. The CMSinterface 824 may be configured to operate in compliance with variousprotocols, standards and/or formats, including but not limited to, theH.323 family of standards, the SIP family of standards, etc. It would beappreciated that by providing a suitably configured CMS interface it maybe possible to setup and manage a real-time CMS between a fake CMSclient and an originator of the real-time CMS, without the originator ofthe real-time CMS being aware of the nature of the recipient.

According to some embodiments of the invention, the fake CMS client 820may be adapted to utilize the reference data generator 822 to generate areference data item based upon real-time CMS media data. According tofurther embodiments of the invention, the fake CMS client 820 may beadapted to utilize the reference data generator 822 to generate areference data item based upon the media data received at the fake CMSclient 820 during a real-time CMS. According to still furtherembodiments of the invention, as part of generating a reference dataitem, the reference data generator 822 may be adapted to monitor theincoming real-time CMS media data being received at the fake CMS client820. The media data generator 822 may be adapted to record certain datain respect of the media data being received at the fake CMS client 820as part of the real-time CMS. According to some embodiments of theinvention, the reference data generator 822 may be adapted to obtain thedata necessary for generating a reference data item directly from thebit-stream (or packet stream) corresponding to the real-time CMS.However, according to still further embodiments of the invention, thereference data generator 822 may obtain the necessary data from thedecoded real-time CMS data. The reference data generator 822 may beconfigured to determine which type of data needs to be obtained and howto obtain that data in accordance with predefined rules. In accordancewith one example of possible rules which may be implemented by thereference data generator 822, the type of data that needs to be obtainedand/or the amount of data necessary for generating a reference dataitem, may depend upon various characteristics of the real-time CMS, suchas for example, the underlying session type, the data flow rate, theoriginator being a suspected source or not, etc. However, it should benoted that further embodiments of the invention are not limited in thisrespect.

By way of example, according to some embodiments of the invention, thereference data generator 822 may be configured to record one or more ofthe following types of data and any combination thereof: a sequence ofgain parameters corresponding to the incoming media data received aspart of the real-time CMS; a sequence of packet arrival timescorresponding to the incoming media data received as part of thereal-time CMS; a sequence of data packet sizes corresponding to theincoming media data received as part of the real-time CMS. It should beappreciated that in accordance with some embodiments of the invention,the reference data generator 822 may be configured to collect and recorddata in respect of other characteristics and/or parameters correspondingto the incoming media data received as part of the real-time CMS andthat such data may be obtained directly from the bit-stream (or packetstream) corresponding to the real-time CMS, or from and based upon thedecoded media data.

As part of the process of generating a reference data item, thereference data generator 822 may be configured to continue collectingdata in respect of a certain real-time CMS until a sufficient amount ofdata is collected. According to some embodiments of the invention, thereference data generator 822 may be configured to implement a referencedata threshold that may be used for determining when the amount of datacollected in respect of a certain real-time CMS is enough to generate areference data item. According to one embodiment of the invention, thereference data threshold may relate to the amount of useful datacollected. Usefulness of data may be associated with potentialcontribution of the data to a similarity evaluation process. Accordingto some embodiments of the invention, as part of generating a referencedata item, the reference data generator 822 may be configured to obtaindata in respect of only specific attributes, characteristics orparameters of the real-time CMS and may disregard the rest of thereal-time CMS data. This data may be used by the reference datagenerator 822 to create some kind of a signature of the real-time CMS.The signature may be used to generate the reference data item. However,according to still further embodiments of the invention, the referencedata generator 822 may be configured to record the entire real-time CMSor the entire encoded bit-stream which corresponds to the real-time CMSas part of generating a reference data item.

According to some embodiments of the invention, if it is determined bythe reference data generator 822, for example, in accordance with areference data criteria, that the initial real-time CMS data received atthe fake CMS client 820 is not sufficient for generating a referencedata item in respect of the real-time CMS, the fake CMS client 820 maybe configured to generate synthetic CMS data that is intended to enticeor stimulate the originator 802 to provide the fake conversation client820 with further real-time CMS data. The fake CMS client 820 maycontinue to generate synthetic CMS data so long as further real-time CMSdata is needed for generating the reference data item. According to someembodiments of the invention, the fake CMS client 820 may include or maybe associated with a media data generation module 828. According to someembodiments of the invention, the media data generation module 828 maybe adapted to generate synthetic CMS data, and in particular syntheticCMS media data. The media data generation module 828 may include a setof heuristics or logic which may be utilized by the media datageneration module 828 to generate the CMS media data. According tofurther embodiments of the invention, the media data generation module828 may include or may be associated with a set of prerecorded CMS mediadata segments which may be used by the media data generation module 828to generate the CMS media data. The media data generation module 828 maybe adapted to use the recording “as is” or to modify them as necessary.

According to some embodiments of the invention, if it is determined, forexample, in accordance with a reference data criterion, that the initialreal-time CMS data received at the fake CMS client 820 is not sufficientfor generating a reference data item in respect of the real-time CMS,the fake CMS client 820 may be configured to utilize the media datageneration module 828 to provide synthetic CMS media data in response tothe media data received from the originator 802 so that the originator802 is stimulated to provide the fake CMS client 820 further CMS mediadata in a manner to enable the fake CMS client 820 to complete thegeneration of the reference data item in respect of the real-time CMS.According to some embodiments of the invention, the media datageneration module 828 may be adapted to generate the media data that isto be used for responding to the originator 802 in a manner to cause theoriginator 802 to engage in conversation with the fake CMS client 820,without becoming suspicious of the nature of the fake CMS client 820.For example, according to some embodiments of the invention, the mediadata generation module 828 may be adapted to adapt or otherwise conformthe media data it generates so that it complies with authentic humanbehaviors. For example, the media data generation module 828 may beadapted to introduce response delays into the real-time CMS in a mannerwhich simulates authentic human behavior. The media data generationmodule 828 may be adapted to continue to generate CMS media data so longas additional media data (from the originator) is required forgenerating the reference data item.

According to some embodiments of the invention, the fake CMS client 820may be configured to generate a reference data item in respect of eachreal-time CMS established with the fake CMS client 820. It would beappreciated, that the fake CMS client 820 is not an authentic CMSclient, and therefore it is not likely to be a participant of alegitimate media conversation session. Accordingly any real-time CMSestablished with the fake CMS client 820 may be regarded a-priori asbeing suspicious. However, according to some embodiments of theinvention, the fake CMS client 820 may be adapted to generate referencedata items only in respect of some of the real-time CMSs establishedwith the fake CMS client 820. The fake CMS client 820 may be adapted toselect in respect of which session to generate a reference data item inaccordance with certain rules or criteria. For example, the fake CMSclient 820 may be configured to determine whether to generate areference data item in respect of a certain real-time CMS establishedtherewith based upon the signaling data associated with the real-timeCMS and/or based upon the media data or some portion thereofcorresponding to the real-time CMS. The fake CMS client 820 may beconfigured to use any suitable similarity evaluation technique or methodfor determining whether to generate a reference data item in respect ofa certain real-time CMS, including but not limited to, any of thesimilarity evaluation processes described above with reference to someaspects of the present invention, and any combination thereof. As partof the similarity evaluation process implemented by the fake CMS client820 various similarity thresholds and unwanted CMS detection criteriamay be utilized.

According to some embodiments of the invention, the reference data itemgenerated by the fake CMS client 820 may be used by a client 804 that isin receipt of the reference data item to detect unwanted CMS traffic.For example, as is shown in FIG. 8 and according to some embodiments ofthe invention, upon receiving the reference data item from the fake CMSclient 820, the client 804 may be configured to store the reference dataitem within a reference database 814. The client 804 or a system fordetecting unwanted CMS data 810 associated with the client 804 may beadapted to use the reference data item as part of a similarityevaluation process implemented by a similarity evaluation module 812 inrespect of a real-time CMS. For example, according to some embodimentsof the invention, the client 804 or a system for detecting unwanted CMSdata 810 associated with the client 804 may be adapted to use thereference data item as part of a similarity evaluation process upondetecting real-time CMS data of which the client 804 is the intendedrecipient. In FIG. 8 the real-time CMS in respect of which the client804 is configured to implement a similarity evaluation process isreferenced “real-time CMS 2”. As part of the similarity evaluationprocess, the similarity evaluation module 812 may be adapted to evaluatethe similarity between real-time CMS 2 and the reference data itemreceived from the fake CMS client 820. As part of evaluating similaritybetween the real-time CMS and the reference data item, the similarityevaluation module 812 may be adapted to implement one or more similarityevaluation processes. It should be appreciated that the similarityevaluation module 812 may be configured to implement any suitablesimilarity evaluation process including, but not limited to: theprogressive similarity process, the direct-bit stream evaluationprocess, and the packet arrival time process, which were described abovein greater detail.

According to some embodiments of the invention, the fake CMS client 820may be further adapted to generate one or more CMS traffic control rulesbased upon signaling data associated with a real-time CMS establishedwith the fake CMS client 820. Detailed discussions in respect of variousembodiments of the invention related to the generation of CMS trafficcontrol rules have been provided above and are applicable with thenecessary modifications to the generation of CMS traffic control rulesby the fake CMS client 820. The fake CMS client 820 may be adapted topublish the CMS traffic control rules, so that clients 804 in receipt ofthe CMS traffic control rules may implement them, in a manner to enablefuture CMS traffic control.

Although according to some embodiments of the invention, there isdisclosed a system which includes a fake conversational client andadditional components, further embodiments of the invention contemplatea configuration whereby the functionality of the additional componentsis incorporated into the fake conversational client.

Reference is now made to FIG. 9, which is a block diagram illustrationof a system for detecting unwanted CMS traffic which includes a CMSproxy, according to some embodiments of the invention. In accordancewith some embodiments of the invention, a system for enabling detectionof unwanted CMS traffic 910 may be implemented as part of or may beassociated with a CMS proxy 903. According to some embodiments of theinvention, the CMS proxy 903 may be positioned between an originator 902of a real-time CMS and an intended recipient 904 of the real-time CMS.According to further embodiments of the invention, the CMS proxy 903 maybe associated with a plurality of nodes, for example, as is shown inFIG. 9, the CMS proxy 903 may be associated with a certain networkdomain 9040 which includes a plurality of nodes 904, 9042, 9043 and9044.

According to some embodiments of the invention, the CMS proxy 903 may beadapted to receive real-time CMS traffic that is intended for of any ofthe nodes or clients 904, 9042, 9043 and 9044 associated with the CMSproxy 903. For example, real-time CMS traffic from an originator 902that is intended for a client 904 associated with the CMS proxy 903 maybe received at the CMS proxy 903 on its way to its destination—client904. The CMS proxy 903 may be configured such that any network trafficwhose intended recipient is one of the nodes associated with the CMSproxy 903 is required to pass through the CMS proxy 903 (this may beachieved, for example, by connecting the nodes network communicationchannels to the CMS proxy 903). According to further embodiments of theinvention, the CMS proxy 903 may be configured such that any real-timeCMS traffic whose intended recipient is one of the nodes associated withthe CMS proxy 903 is required or forced to pass through the CMS proxy903.

As mentioned above, the CMS proxy 903 may include or may be associatedwith a system for detecting unwanted CMS traffic 910. According to someembodiments of the invention, the CMS proxy 903 may include or may beassociated with a similarity evaluation module 912 and a referencedatabase 914. The reference database 914 may include one or morereference data items. According to some embodiments, the referencedatabase 914 may include data in respect of previous CMSs intended to bereceived by any of the nodes associated with the CMS proxy 903.According to further embodiments of the invention, the referencedatabase 914 may include reference data items received from externalsources, such as for example, from a fake CMS client that the CMS proxyis a subscriber of. Each reference data item may correspond to aprevious CMS or to a portion of a previous CMS. The reference data itemsmay be used as part of the similarity evaluation process to determinewhether the real-time CMS (or some portion thereof) is similar to aprevious CMS. The similarity evaluation module 912 may be adapted toimplement a similarity evaluation process in respect of the real-timeCMS received by the CMS proxy 903. According to some embodiments of theinvention, the CMS proxy 903 may utilize the similarity evaluationmodule 912 to implement a similarity evaluation process in respect of atleast a portion of the real-time CMS data received from the originator902 at the CMS proxy 903. According to some embodiments of theinvention, the similarity evaluation process implemented by thesimilarity evaluation module 912 may be configured to determine whethera media portion of a real-time CMS and a reference data item associatedwith a previous CMS are similar enough (e.g. is above a similaritythreshold(s)). Examples of various approaches to similarity evaluationwere described in greater detail above. It should be appreciated thatthe similarity evaluation module 912 employed by the CMS proxy 903 maybe configured to implement any of the similarity evaluation processesdisclosed above and any combination thereof. According to furtherembodiments of the invention, the similarity evaluation module 912employed by the CMS proxy 903 may be configured to implement anyadditional similarity evaluation process suitable for evaluatingsimilarity between a set of values associated with a real-time CMS (orsome portion thereof) and a reference data item associated with aprevious CMS (or some portion thereof).

The CMS proxy 903 may be adapted to utilize a similarity evaluationmodule 912 to implement a similarity evaluation process. The CMS proxy903 may cause the similarity evaluation process to be implemented aspart of a process of detecting unwanted CMS traffic. According to someembodiments of the invention, the proxy 903 may be configured todetermine whether the real-time CMS is unwanted based on the results ofthe similarity evaluation process. According to some embodiments of theinvention, once the CMS proxy 903 determines that the real-time CMS isunwanted or that a certain portion of the real-time CMS is unwanted, theCMS proxy 903 may terminate or discontinue the real-time CMS or mayremove an unwanted portion of the real-time CMS, thereby preventing itfrom reaching the intended recipient 904. The relationship between thesimilarity evaluation process and the process for detecting unwanted CMStraffic were discussed in detail above and it would be appreciated thatthese discussions may be applied mutatis mutandis to embodiments of theinvention which include the system for detecting unwanted CMS traffic910 employed by the CMS proxy 903. It should be appreciated thataccording to some embodiments of the invention, the CMS proxy 903 may beconfigured to altogether prevent unwanted real-time CMS traffic fromreaching the intended recipient 904 or, in accordance with furtherembodiments of the invention, it may be configured to break off a CMSsession with the intended recipient 904 once it is determined that thereal-time CMS is unwanted. Examples in accordance with some embodimentsof the invention which relate to configurations of the CMS proxy 903which enable the CMS proxy 903 to altogether prevent unwanted real-timeCMS traffic from reaching the intended recipient 904 are provided below.Further examples in accordance with further embodiments of the inventionwhich relate to configurations of the CMS proxy 903 which enable the CMSproxy 903 to break off a CMS session with the intended recipient 904once it is determined that the real-time CMS is unwanted are alsoprovided below.

The initial real-time CMS data received at the CMS proxy 903 (from theoriginator 902) may not be sufficient or may not be appropriate forevaluating similarity between the real-time CMS and a reference dataitem. In this context, it would be appreciated that typically theinitial real-time CMS data exchanges include CMS signaling data that isnecessary for setting up a real-time CMS media data exchange. In suchcases, the CMS proxy 903 may be adapted to establish a real-time CMSwith the originator 902 in order to obtain sufficient real-time CMSmedia data so as to enable the CMS proxy 903 to implement a similarityevaluation process in respect of the real-time CMS, as part of a processof detecting unwanted real-time CMS traffic.

According to some embodiments of the invention, upon receiving from anoriginator 902 real-time CMS traffic intended for a node 904 associatedwith the CMS proxy 903, the CMS proxy 903 may be configured to setup areal-time CMS with the originator 902 of the real-time CMS. The CMSproxy 903 may be configured to use the (additional) data received fromthe originator 902 during the real-time CMS established therewith toevaluate the similarity of the real-time CMS media data received fromthe originator with a reference data item corresponding to a previousCMS. According to further embodiments of the invention, the CMS proxy903 may be configure to enable the CMS data intended for the recipient904 to reach the recipient 904 only through the CMS session establishedbetween the originator 902 and the CMS proxy 903, as will be describedin further detail below.

According to some embodiments of the invention, the CMS proxy 903 mayinclude or may be associated with an originator interface (IF) 913. Theoriginator IF 913 may be configured to setup a real-time CMS between theCMS proxy 903 and the originator 902 of the CMS traffic intended fromone of the nodes associated with the CMS proxy 903. According to someembodiments of the invention, upon detecting real-time CMS traffic thatis intended for a node 904 associated with the CMS proxy 903, theoriginator IF 913 may be adapted to setup a real-time CMS between theCMS proxy 903 and the originator 902 of the real-time CMS traffic.

According to some embodiments of the invention, the CMS proxy 903 may beadapted to use data with respect to the intended recipient 904 of thereal-time CMS traffic to generate signaling data that is to be used forsetting up the real-time CMS between the CMS proxy 903 and theoriginator 902. For example, the CMS proxy 903 may be configured to usethe network address of the intended recipient 904 to generate signalingdata. According to still further embodiments of the invention, the CMSproxy 903 may use the signaling data correlated with the intendedrecipient 902 of the real-time CMS in a manner to cause the originator902 of the real-time CMS to identify the CMS proxy 903 as the intendedrecipient of the real-time CMS. Thus the originator 902 of the real-timeCMS may be kept unaware of the participation of the CMS proxy 903 in thereal-time CMS.

According to some embodiments of the invention, once the real-time CMSbetween the originator 902 and the CMS proxy 903 is setup, real-time CMSmedia data may be exchanged between the originator 902 and the CMS proxy903. According to some embodiments of the invention, the CMS proxy 903may be configured to stimulate the originator 902 to provide the CMSproxy 903 with additional real-time CMS media data. It would beappreciated that according to some embodiments of the invention, acertain amount of CMS media data may be required by a similarityevaluation process implemented by a similarity evaluation module 912 forthe similarity evaluation module 912 to be able to make a determinationin respect of similarity. According to some embodiments of theinvention, the CMS proxy 903 may be configured to respond to real-timeCMS media data received from the originator 902 with appropriatereal-time CMS media data, in order to stimulate the originator 902 toprovide the CMS proxy 903 with additional real-time CMS media data.

According to some embodiments of the invention, the CMS proxy 903 may beconfigured to generate CMS media and communicate the generated CMS datato the originator 902, so as to stimulate the originator 902 to providethe CMS proxy 903 with further real-time CMS media data. The CMS proxy903 may include a media generation module (not shown) operative forgenerating real-time CMS media data. The media generation module may beconfigured to generate real-time CMS media data responsive to CMS mediadata received from the originator 902 during the real-time CMS. Themedia generation module may include appropriate logic so as to enablethe generation of appropriate real-time CMS media data. The mediageneration module may include pre-recorded CMS media data, and may usethe prerecorded media data to generate appropriate media data response.Further details in connection with one example of a media generationmodule were provided above with reference to the system for detectingunwanted CMS shown in FIG. 8, and are applicable with any necessarymodifications. However, in accordance with further embodiments of theinvention, as will be described in greater detail below, as analternative to generating real-time CMS media data, or in addition, theCMS proxy 903 may be configured to obtain CMS media data from theintended recipient 904 of the real-time CMS traffic received at the CMSproxy 903. According to further embodiments of the invention, the CMSproxy 903 may be configured to obtain from the intended recipient 904CMS media data that is responsive to the real-time CMS media datareceived from the originator 902 over the real-time CMS establishedbetween the originator 902 and the CMS proxy 903.

As mentioned above, the CMS proxy 903 may be adapted to receivereal-time CMS traffic that is intended for any of the nodes or clients904, 9042, 9043 and 9044 associated with the CMS proxy 903. In a similarway, according to some embodiments of the invention, the CMS proxy 903may be adapted to receive outbound real-time CMS traffic from any of thenodes or clients 904, 9042, 9043 and 9044 associated with the CMS proxy903. The CMS proxy 903 may be configured such that any outbound networktraffic from the nodes associated with the CMS proxy 903 is required topass through the CMS proxy 903. According to further embodiments of theinvention, the CMS proxy 903 may be configured such that any outboundnetwork traffic from the nodes associated with the CMS proxy 903 isforced to pass through the CMS proxy 903.

According to some embodiments of the invention, upon receiving real-timeCMS traffic intended for a node 904 associated with the CMS proxy 903,the CMS proxy 903 may be configured to setup a CMS with the intendedrecipient 904 of the real-time CMS. According to further embodiments ofthe invention, the CMS proxy 903 may be configured to enable to CMS dataintended for the recipient 904 to reach the recipient only through theCMS session established between the CMS proxy 903 and the intendedrecipient 904, as will be described in further detail below.

According to some embodiments of the invention, the CMS proxy 903 mayinclude or may be associated with a client interface (IF) 915. Theclient IF 915 may be configured to setup the CMS with the nodesassociated with the CMS proxy 903. According to some embodiments of theinvention, upon receiving real-time CMS traffic that is intended for anode 904 associated with the CMS proxy 903, the client IF 915 may beadapted to setup a CMS between the CMS proxy 903 and the intendedrecipient 904 of the real-time CMS. According to some embodiments of theinvention, the CMS proxy 903 may be adapted to use certain signalingdata received from the originator 902 of the real-time CMS to generatethe signaling data that is to be used for setting up the CMS between theCMS proxy 903 and the intended recipient 904 of the real-time CMS.According to still further embodiments of the invention, the CMS proxy903 may use the signaling data received from the originator 902 of thereal-time CMS in a manner to cause the intended recipient 904 of thereal-time CMS to identify the originator of the CMS with the CMS proxy903 as being the originator 902 of the real-time CMS intercepted by theCMS proxy 903.

According to some embodiments of the invention, the CMS proxy 903 may beconfigured to maintain the real-time CMS with the originator 902 atleast so long as there is a need for additional CMS data (and inparticular for CMS media data) for evaluating similarity between thereal-time CMS and a reference data item correlated with a previous CMSand/or for determining whether the real-time CMS is unwanted.

It should be appreciated that according to some embodiments of theinvention, by establishing back-to-back sessions through the CMS proxy903 with the originator 902 on the one hand and the intended recipient904 on the other, in a manner whereby the CMS proxy 903 is transparentto the either participants (the originator 902 being under theimpression that it is communicating with the intended recipient 904 andthe intended recipient 904 being under the impression that it iscommunicating with the originator 902), the CMS proxy 903 may be able tocreate an indirect communication link through the CMS proxy 903 which issubstantially equivalent in some respect to a real-time CMS between theoriginator 902 and the intended recipient 904. It would be furtherappreciated that the above disclosed communication scheme supported andenabled by the CMS proxy 903 allows the CMS proxy 903 to overcomepotential encryption of the real-time CMS traffic due to the fact thatthe real-time CMS is terminated at the CMS proxy 903.

Furthermore, as mentioned above, according to some embodiments of theinvention, the CMS proxy 903 may be associated with and provide serviceto a plurality of nodes. Thus the resources required for detecting andhandling unwanted CMS traffic may be centralized. It would beappreciated that a centralized CMS traffic control solution may be moreefficient and potentially less costly. Furthermore, a centralizedsolution may allow for a more comprehensive reference database, since itmay be more simply updated with data relating to CMS traffic whoseintended recipient is any of the nodes associated with the CMS proxy.

According to some embodiments of the invention, either in addition tothe similarity evaluation approach towards detecting unwanted CMStraffic, or as an alternative, the CMS proxy 903 may be configured toimplement CMS traffic control rules associated with CMS signaling datato detect unwanted CMS traffic. For example, according to someembodiments of the invention, the CMS proxy 903 may be adapted toimplement a certain CMS control rule in accordance with which anyreal-time CMS traffic whose signaling data is equal to or otherwiseassociated with certain signaling data prescribed by the CMS trafficcontrol rule is unwanted. In accordance with another example, the CMSproxy 903 may be adapted to implement a certain CMS control rule inaccordance with which any real-time CMS traffic whose signaling data isequal to or otherwise associated with certain signaling data prescribedby the CMS traffic control rule is suspected of being unwanted.According to some embodiments of the invention, upon determining that acertain real-time CMS is suspected of being unwanted, the CMS proxy 903may be configured to adjust a similarity evaluation process that is tobe implemented in respect of the real-time CMS. According to furtherembodiments of the invention, as part of adjusting a similarityevaluation process, the CMS proxy 903 may be configured to adjust one ormore of the following: one or more similarity thresholds implemented bythe similarity evaluation process; the amount of data required toestablish similarity (or lack thereof), and/or any other parameterassociated with the similarity evaluation process.

The invention was described with reference to various aspects thereof.It would be appreciated that while some embodiments of the invention areapplicable to only one or to only some aspects of the invention, mayother embodiments of the invention are application to further aspects ofthe invention. Furthermore, some embodiments of the invention have beendescribed with reference to a particular aspect or aspects and forreasons and convenience and/or clarity may not have been explicitlyreplicated as part of the description of further aspects of theinvention. In this regard, the application should be considered as awhole, and various embodiments of the invention described with referenceto a specific aspect or aspects may also be applicable, in accordancewith further embodiments of the invention to a further aspect of theinvention, despite not being specifically disclosed with respect to thataspect, unless it is apparent to a person with ordinary skill in the artthat such ascription is under relevant circumstances inappropriate.

While certain features of the invention have been illustrated anddescribed herein, many modifications, substitutions, changes, andequivalents will occur to those skilled in the art. It is therefore tobe understood that the appended claims are intended to cover all suchmodifications and changes as fall within the true scope of theinvention.

1. A method of detecting unwanted conversational media session data,said method comprising: calculating two or more progressive similarityscores each with respect to a different instant during a progress of areal-time conversational media session (hereinafter: “CMS”), whereineach of said scores is associated with a similarity between the CMS'smedia data that was available at the associated instant and a referencedata item corresponding to media data of a previous CMS; and evaluatingprogressive similarity between the real-time CMS and the reference dataitem based upon the two or more progressive similarity scores.
 2. Themethod according to claim 1, wherein said calculating is performedon-the-fly during the progress of the real-time CMS.
 3. The methodaccording to claim 2, wherein each of said similarity scores issensitive to the amount of the extent of media data available at theinstant with which the score is associated.
 4. The method according toclaim 1, wherein said reference data item includes one or more of thefollowing: a. a recording of a previous CMS or of a portion of aprevious CMS; b. a signature of a previous CMS or of a portion of aprevious CMS; c. a schematic representation providing progressionschemes of one or more components of the previous CMS or of a portion ofa previous CMS.
 5. The method according to claim 1, wherein saidcalculating comprises: calculating a first similarity score with respectto a first amount of media data available at a first instant during theprogress of the real-time CMS; and calculating a second similarity scorewith respect to a second amount of media data available at a secondinstant during the progress of the real-time CMS, wherein said secondinstant succeeds said first instant.
 6. The method according to claim 5,wherein said second amount of media data includes the first amount ofmedia data and the media data received between said first and secondinstants.
 7. The method according to claim 5, wherein said second amountof media data includes the media data received between said first andsecond instants.
 8. The method according to claim 1, wherein saidevaluating comprises implementing a unwanted CMS detection criteria,said CMS detection criteria being associated with at least a progressivesimilarity criterion, and wherein the progressive similarity criterionis usable for determining based upon two or more progressive similarityscores whether the real-time CMS and the reference data item aresimilar.
 9. The method according to claim 8, wherein in accordance withthe unwanted CMS detection criteria a unwanted real-time CMS is areal-time CMS which complies with at least one progressive similaritycriterion.
 10. The method according to claim 8, wherein the unwanted CMSdetection criteria further includes a progressive dissimilaritycriterion, and wherein the progressive dissimilarity criterion is usablefor determining based upon one or more progressive similarity scoreswhether the real-time CMS and the reference data item are dissimilar.11. The method according to claim 9, wherein the progressive similaritycriterion includes a progressive similarity threshold and wherein saidevaluating includes implementing the progressive similarity thresholdfor determining whether a progressive similarity score(s) is indicativeof similarity between the real-time CMS and the reference data item. 12.The method according to claim 10, wherein the progressive similaritycriterion includes a progressive dissimilarity threshold usable fordetermining whether a progressive similarity score(s) is indicative ofdissimilarity between the real-time CMS and the reference data item. 13.The method according to claim 12, wherein said evaluating comprisesdetermining based upon the two or more progressive similarity scoreswhether the real-time CMS and the reference data item are similar,dissimilar or that further progressive similarity scores are necessaryto determine similarity or dissimilarity.
 14. The method according toclaim 9, wherein said calculating is an iterative process and as part ofeach iteration thereof a progressive similarity score is calculated, andwherein said calculating is continued until enough real-time CMS data isavailable to determine in accordance with the unwanted CMS criteriawhether the real-time CMS is unwanted.
 15. The method according to claim14, wherein in accordance with the unwanted CMS detection criteria theamount of data real-time CMS data required to determine that thereal-time CMS is unwanted is associated with at least one or moreprogressive similarity scores calculated for the real-time CMS and areference data item.
 16. The method according to claim 8, wherein saidunwanted CMS detection criteria is further associated with a CMS trafficcontrol rule, and wherein the CMS traffic control rule is usable foradjusting the progressive similarity criterion based upon the signalingdata associated with the real-time CMS.
 17. The method according toclaim 16, wherein adjusting the progressive similarity criterioncomprises identifying an originator of the real-time CMS and adjustingthe progressive similarity criterion if it is determined the real-timeCMS is associated with a certain originator or with a certain group oforiginators.
 18. The method according to claim 16, further comprisinggenerating a CMS traffic control rule based upon real-time CMS'ssignaling data in case it is determined that the real-time CMS issimilar to one or more reference data items.
 19. The method according toclaim 98, further comprising discontinuing the real-time CMS once it isestablished that the real-time CMS complies with the unwanted CMSdetection criterion.
 20. The method according to claim 9, furthercomprising blocking the real-time CMS upon establishing that thereal-time CMS complies with the unwanted CMS detection criterion andbefore the real-time CMS is initiated at its intended recipient.
 21. Themethod according to claim 8, wherein the unwanted CMS detection criteriaincludes one or more tolerance values, said tolerance values beingconfigured to accommodate for one or more of the following: expectedpacket loss over the network, constant delay between MSCs and delayvariation or jitter between MSCs.
 22. The method according to claim 1,further comprising utilizing an intermediary CMS monitoring unit tointercept real-time CMS data traversing the network, wherein saidcalculating and evaluating is performed in respect of the interceptedreal-time CMS and a previously intercepted CMS.
 23. The method accordingto claim 22, wherein said intermediary CMS monitoring unit is utilizedin a manner to enable the interception of real-time CMS data fromnonspecific originators and/or to enable the interception of real-timeCMS data traversing the network towards nonspecific recipients.
 24. Themethod according to claim 1, further comprising providing a plurality ofreference data items for a real-time CMS and performing said calculatingand evaluating in respect of each of the plurality of reference dataitems.
 25. A system for detecting unwanted conversational mediasessions, said system comprising: a reference database including one ormore reference data items, each reference data item corresponding tomedia data of a previous CMS; and a progressive similarity evaluationmodule (hereinafter: “PSE module”), said PSE module being adapted tocalculate two or more progressive similarity scores each with respect toa different instant during a progress of a real-time CMS, wherein eachof said scores is associated with a similarity between the CMS's mediadata that was available at the associated instant and a reference dataitem, and said PSE module being further adapted to evaluate progressivesimilarity between the real-time CMS and the reference data item basedupon the two or more progressive similarity scores.
 26. The systemaccording to claim 25, wherein at least said PSE module is associatedwith an intended recipient of the real-time CMS.
 27. The systemaccording to claim 25, wherein at least said PSE module is associatedwith a CMS monitoring node, said CMS monitoring node including aninterception module for enabling the CMS monitoring node to interceptreal-time CMS data from nonspecific originators and/or to interceptreal-time CMS data traversing the network towards nonspecificrecipients.
 28. The system according to claim 27, wherein said CMSmonitoring node further comprises a CMS media simulator, said CMS mediasimulator being adapted to generate real-time CMS media data in responseto real-time CMS data intercepted by the interception module.
 29. Amethod of detecting unwanted conversational media sessions, said methodcomprising: obtaining a sequence of significant attributes directly froma bit-stream corresponding to a real-time CMS; and evaluating similaritybetween the sequence of significant attributes associated with thereal-time CMS and a reference data item corresponding to a sequence ofsignificant attributes of a bit-stream associated with a previous CMS.30. The method according to claim 29, wherein said significantattributes include one or more of the following: gain parameters; gainparameters of adapted and/or fixed codebooks, spectral parameters;spectral parameters coded as Line Spectral Pair.
 31. The methodaccording to claim 29, wherein the bit-stream provides the encodedreal-time CMS data.
 32. The method according to claim 29, wherein saidevaluating further comprises calculating two or more progressivesimilarity scores each with respect to a different instant during aprogress of a real-time CMS, wherein each of said scores corresponds tothe similarity between the significant attributes associated with thereal-time CMS data available at the corresponding instant and thereference data, and wherein said evaluating further comprises evaluatingprogressive similarity between the real-time CMS data and the referencedata based upon the two or more progressive similarity scores.
 33. Themethod according to claim 29, further comprising utilizing anintermediary CMS monitoring node to intercept real-time CMS datatraversing the network, wherein said calculating and evaluating isperformed in respect of the intercepted real-time CMS data and apreviously intercepted CMS.
 34. The method according to claim 29,wherein said evaluating comprises implementing a unwanted CMS detectioncriteria, said unwanted CMS detection criteria being associated with atleast a similarity criterion, and wherein said similarity criterion isusable for determining whether the real-time CMS and the reference dataitem are similar based upon at least a sequence of significantattributes associated with the real-time CMS and a reference data item.35. The method according to claim 34, further comprising generating aCMS traffic control rule based upon real-time CMS's signaling data incase it is determined that the real-time CMS is similar to one or morereference data items.
 36. The method according to claim 35, wherein theCMS traffic control rule is applied in a manner to cause the similaritycriterion to be adjusted based upon the signaling data associated withthe real-time CMS.
 37. The method according to claim 29, furthercomprising discontinuing the real-time CMS session once it isestablished that the real-time CMS complies with the unwanted CMSdetection criterion.
 38. The method according to claim 29, wherein thereference data item includes at least a sequence of significantattributes taken directly from the bit-stream of a previous CMS.
 39. Asystem for detecting unwanted conversational media sessions, said systemcomprising: a reference database including one or more reference dataitems, each reference data item including data in respect of a sequenceof significant attributes taken directly from a bit-stream of a previousCMS; and a bit-stream similarity evaluation module adapted to obtain asequence of significant attributes directly from a bit-streamcorresponding to a real-time CMS, and being further adapted to evaluatesimilarity between the sequence of significant attributes associatedwith the real-time CMS and a reference data item.
 40. The systemaccording to claim 39, wherein at least said bit-stream similarityevaluation module is associated with an intended recipient of thereal-time CMS.
 41. The system according to claim 29, wherein at leastsaid bit-stream similarity evaluation module is associated with a CMSmonitoring node, said CMS monitoring node including an interceptionmodule for enabling the CMS monitoring node to intercept a bit-streamcorresponding to a real-time CMS data from nonspecific originatorsand/or to intercept a bit-stream corresponding to a real-time CMS datatraversing the network towards nonspecific recipients.
 42. The systemaccording to claim 41, wherein said CMS monitoring node furthercomprises a CMS media simulator, said CMS media simulator being adaptedto generate real-time CMS media data in response to real-time CMS dataintercepted by the interception module.
 43. A method of detectingunwanted conversational media sessions, said method comprising:obtaining data in respect of packet arrival times associated with areal-time CMS; and evaluating similarity between data in respect of thepacket arrival times associated with the real-time CMS and a referencedata item corresponding to packet arrival times associated with aprevious CMS.
 44. The method according to claim 43, wherein the data inrespect of the packet arrival times includes one or more of thefollowing: packet inter-arrival times and packet sizes.
 45. The methodaccording to claim 44, wherein said evaluating comprises evaluatingsimilarity between data in respect of the packet arrival times andpacket sizes associated with the real-time CMS and a reference data itemincluding data in respect of packet arrival times and packet sizesassociated with a previous CMS
 46. The method according to claim 43,wherein the data in respect of packet arrival times is obtained directlyin respect from a bit-stream corresponding to the real-time CMS.
 47. Themethod according to claim 43, wherein said evaluating further comprisescalculating two or more progressive similarity scores each with respectto a different instant during a progress of a real-time CMS, whereineach of said scores corresponds to the similarity between the packetarrival times associated with the real-time CMS data which wereavailable at the corresponding instant and the reference data item, andwherein said evaluating further comprises evaluating progressivesimilarity between the real-time CMS data and the reference data itembased upon the two or more progressive similarity scores.
 48. The methodaccording to claim 43, wherein said obtaining and evaluating isperformed in respect of real-time CMS traffic whose intended recipientis a specific network node or a network node that belongs to a specificgroup of network nodes.
 49. The method according to claim 43, furthercomprising utilizing an intermediary CMS monitoring node to interceptreal-time CMS data traversing the network, wherein said obtaining andevaluating is performed in respect of the intercepted real-time CMS dataand a previously intercepted CMS.
 50. The method according to claim 43,wherein said evaluating comprises implementing a unwanted CMS detectioncriteria, said unwanted CMS detection criteria being associated with atleast a similarity criterion, and wherein said similarity criterion isusable for determining whether the real-time CMS and the reference dataitem are similar based upon at least data in respect of packet arrivaltimes associated with the real-time CMS and a reference data item. 51.The method according to claim 50, further comprising generating a CMStraffic control rule based upon real-time CMS's signaling data in caseit is determined that the real-time CMS is similar to one or morereference data items.
 52. The method according to claim 51, wherein theCMS traffic control rule is applied in a manner to cause the similaritycriterion to be adjusted based upon the signaling data associated withthe real-time CMS.
 53. The method according to claim 50, furthercomprising discontinuing the real-time CMS session once it isestablished that the real-time CMS complies with the unwanted CMSdetection criterion.
 54. A system for detecting unwanted conversationalmedia sessions, said system comprising: a reference database includingone or more reference data items, each reference data item includingdata in respect of a packet arrival times associated with a previousCMS; and a packet arrival similarity evaluation module adapted to datain respect of packet arrival times associated with a real-time CMS, andbeing further adapted to evaluate similarity between the data in respectof the packet arrival times associated with the real-time CMS and areference data item.
 55. The system according to claim 54, wherein saidpacket arrival similarity evaluation module is adapted to obtain thedata in respect of the packet arrival times associated with a real-timeCMS directly from a bit-stream associated with the real-time CMS. 56.The system according to claim 55, wherein the data in respect of thepacket arrival times includes one or more of the following: packetinter-arrival times and packet sizes.
 57. A method of detecting unwantedconversational media sessions, said method comprising: utilizing a fakeconversation client in a manner to cause an originator of real-time CMSdata to setup and initiate a real-time CMS with the fake conversationclient; and generating a reference data item based upon at least a mediaportion of the real-time CMS data received the fake conversation client;and publishing the reference data in a manner to enable a client inreceipt of the reference data item to control real-time CMS datareceived at the client using the reference data item.
 58. The methodaccording to claim 57, wherein the reference data item is configured toenable evaluation of similarity between the reference data item and areal-time CMS and to enable control over the real-time CMS based uponresults of the similarity evaluation.
 59. The method according to claim57, wherein said utilizing the fake conversation client comprises:interfacing the real-time CMS data to enable setup of the real-time CMSon the fake CMS client; and generating synthetic CMS data intended forcausing an originator of the real-time CMS to provide the fakeconversation client with further real-time CMS data.
 60. The methodaccording to claim 59, wherein said generating comprises generatingsynthetic CMS data responsive real-time CMS data received at the fakeconversation client in a manner to cause an impression of a humangenerated response.
 61. The method according to claim 59, wherein saidgenerating comprises invoking prerecorded CMS data in response toreal-time CMS data received at the fake conversation client.
 62. Themethod according to claim 57, wherein said generating a reference dataitem comprises one or more of the following: recording data in respectof at least a media portion of the real-time CMS received at the fakeconversation client; recording data in respect of at least packetarrival times corresponding to the real-time CMS; recording at least asequence of significant attributes directly from a bit-streamcorresponding to the real-time CMS.
 63. The method according to claim57, wherein said utilizing a fake conversation client comprisesutilizing a plurality of fake CMS clients, and wherein said publishingfurther comprises publishing the reference data items generated by theplurality of fake clients in a manner to enable a client in receipt ofthe reference data items to control incoming real-time CMS traffic basedupon a similarity between the incoming real-time CMS data and thereference data items received from the plurality of fake conversationclients.
 64. The method according to claim 57, further comprisingcreating a CMS traffic control rule based upon signaling data associatedwith the real-time CMS, and wherein said publishing further comprisespublishing the CMS traffic control rule in a manner to enable a clientin receipt of the CMS traffic control rule to control incoming real-timeCMS traffic in accordance with the CMS traffic control rule.
 65. Themethod according to claim 64, wherein the CMS traffic control rulecorresponds to one or more of the following: a network address of anoriginator of real-time CMS; a range of network addresses which includesa network address of an originator of real-time CMS; a usernameassociated with an originator of a real-time CMS.
 66. The methodaccording to claim 57, further comprising: generating a traffic controlrule based upon signaling data associated with the real-time CMSestablished with the fake CMS client; and publishing the CMS trafficcontrol rule in a manner to enable a client in receipt of the CMStraffic control rule to control real-time CMS data received at theclient in accordance with the CMS traffic control rule.
 67. A system fordetecting unwanted conversational media sessions, said systemcomprising: a fake conversation client adapted to cause an originator ofreal-time CMS data to setup and initiate a real-time CMS with said fakeconversation client; a reference data generation module adapted togenerate a reference data item based upon at least a media portion ofthe real-time CMS data received at said fake conversation client; and areference data publisher adapted to publish the reference data itemgenerated by said reference data generation module in a manner to enablea client in receipt of the reference data item to use the reference dataitem to control real-time CMS data received at the client.
 68. Thesystem according to claim 67, further comprising: a CMS interfaceadapted to interface the real-time CMS data to enable setup of thereal-time CMS on the fake CMS client; a media data generation module,said media data generation module being adapted to generate syntheticCMS data intended for causing an originator of the real-time CMS toprovide said fake conversation client with further real-time CMS data.69. The system according to claim 68, where said media data generationmodule is configured to use or more of the following to generate thesynthetic CMS data: a set of a heuristics; a certain logic; prerecordedCMS media data.
 70. A method of detecting unwanted conversational mediasessions, said method comprising: providing a conversation proxypositioned between an originator of a real-time CMS and a client that isthe intended recipient of the real-time CMS, in a manner to cause theoriginator of the real-time CMS to setup the real-time CMS intended forthe client through the proxy; evaluating similarity between media dataof the real-time CMS and a reference data item associated with aprevious CMS; and controlling the real-time CMS based upon a result ofsaid evaluating.
 71. The method according to claim 70, wherein saidcontrolling comprises executing an action with respect to the real-timeCMS in case it is determined that the similarity between the real-timeCMS's media data and the reference data is in compliance with asimilarity criterion, wherein the action is selected from a groupconsisting of: continue said evaluating similarity between the real-timeCMS's media data and reference data based upon at a later instant duringa progress of the a real-time CMS and based upon a larger amount ofreal-time CMS media data available at the later instant; remove certainmedia data from the real-time CMS prior to forwarding the correspondingCMS data to the client or to the originator; and discontinue thereal-time CMS.
 72. The method according to claim 70, wherein saidevaluating comprises evaluating similarity between the real-time CMS'smedia data and the reference data in accordance with one or more of thefollowing: similarity between at least a portion of the real-time CMSand the reference data item; progressive similarity between thereal-time CMS and the reference data item; similarity between a sequenceof significant attributes obtained directly from a bit-streamcorresponding to the real-time CMS and reference data item correspondingto a sequence of significant attributes of a bit-stream associated witha previous CMS; similarity between packet arrival statistics associatedwith the real-time CMS and reference data item corresponding to packetarrival statistics associated with a previous CMS.
 73. The methodaccording to claim 70, wherein said proxy is associated with a pluralityof clients, and wherein the reference data is generated based upon oneor more previous real-time CMS's whose intended recipient was any of theplurality of clients associated with the proxy.
 74. The method accordingto claim 70, further comprising creating a CMS traffic control rulebased upon signaling data associated with the real-time CMS in case itis determined that the similarity between the real-time CMS andreference data item is in compliance with a similarity criterion. 75.The method according to claim 74, further comprising implementing theCMS traffic control rules in respect of future CMS traffic, wherein saidimplementing comprises controlling future real-time CMS traffic whoseintended recipient is a client associated with the proxy in accordancewith the CMS traffic control rule.
 76. The method according to claim 74,wherein said signaling data includes one or more of the followingsignaling data: an originator's network address; an originator's networkdomain; a subject description;
 77. The method according to claim 70,further comprising interfacing the real-time CMS data arriving from theoriginator and the real-time CMS data arriving from the client throughthe proxy to enable setting up of the of the real-time CMS between theoriginator and the client through the conversation proxy.
 78. The methodaccording to claim 77, further comprising establishing a first real-timeCMS between the originator of the real-time CMS and the conversationproxy using signaling data associated with the intended client, andestablishing a second real-time CMS between the conversation proxy andthe client using signaling data associated with the originator, therebyenabling CMS data exchanges between the originator and the clientthrough the proxy.
 79. The method according to claim 78, wherein saidestablishing the real-time CMS between the originator and theconversation proxy and said establishing the real-time CMS between theconversation proxy and the client is performed in a manner to render theproxy transparent to the originator and to the recipient.
 80. A systemfor detecting unwanted conversational media sessions, said systemcomprising: a conversation proxy positioned between an originator of areal-time CMS and a client that is an intended recipient of thereal-time CMS, said conversation proxy being adapted to cause theoriginator of the real-time CMS to setup the real-time CMS intended forthe client through the proxy; and a similarity evaluation module adaptedto implement a similarity evaluation process to evaluate similaritybetween media data of the real-time CMS and a reference data itemassociated with a previous CMS, wherein said conversation proxy isadapted to control the real-time CMS based upon data results of thesimilarity evaluation process.
 81. The system according to claim 80,further comprising a reference database, said reference databaseincluding a plurality of reference data items, wherein each referencedata item includes at least data in respect of media data correspondingto a previous CMS.
 82. The system according to claim 80, wherein saidconversation proxy comprises: an originator interface adapted toestablish a first real-time CMS between the originator of the real-timeCMS and the conversation proxy using signaling data associated with theintended client; and a client interface adapted to establish a secondreal-time CMS between the conversation proxy and the client usingsignaling data associated with the originator, wherein said originatorinterface and said client interface are configured to operate in amanner to enable CMS data exchanges between the originator and theclient through the proxy.